William of Tyre William of Tyre ( c . 1130 – 29 September 1186 ) was a medieval prelate and chronicle r . As archbishop of Tyre , he is sometimes known as William II to distinguish him from a predecessor , William of Malines . He grew up in Jerusalem at the height of the Kingdom of Jerusalem , which had been established in 1099 after the First Crusade , and he spent twenty years studying the liberal arts and canon law in the universities of Europe . Following William ' s return to Jerusalem in 1165 , King Amalric I made him an ambassador to the Byzantine Empire . William became tutor to the king ' s son , the future King Baldwin IV , whom William discovered to be a leper . After Amalric ' s death , William became chancellor and archbishop of Tyre , two of the highest offices in the kingdom , and in 1179 William led the eastern delegation to the Third Council of the Lateran . As he was involved in the dynastic struggle that developed during Baldwin IV ' s reign , his importance waned when a rival faction gained control of royal affairs . He was passed over for the prestigious Patriarchate of Jerusalem , and died in obscurity , probably in 1186 . William wrote an account of the Lateran Council and a history of the Islamic states from the time of Muhammad . Neither work survives . He is famous today as the author of a history of the Kingdom of Jerusalem . William composed his chronicle in excellent Latin for his time , with numerous quotations from classical literature . The chronicle is sometimes given the title " Historia rerum in partibus transmarinis gestarum " ( " History of Deeds Done Beyond the Sea " ) or " Historia Ierosolimitana " ( " History of Jerusalem " ) , or the " Historia " for short . It was translated into French soon after his death , and thereafter into numerous other languages . Because it is the only source for the history of twelfth - century Jerusalem written by a native , historians have often assumed that William ' s statements could be taken at face value . However , more recent historians have shown that William ' s involvement in the kingdom ' s political disputes resulted in detectable biases in his account . Despite this , he is considered the greatest chronicler of the crusades , and one of the best authors of the Middle Ages . Early life . The Kingdom of Jerusalem was founded in 1099 at the end of the First Crusade . It was the third of four Christian territories to be established by the crusaders , following the County of Edessa and the Principality of Antioch , and followed by the County of Tripoli . Jerusalem ' s first three rulers , Godfrey of Bouillon ( 1099 – 1100 ) , his brother Baldwin I ( 1100 – 1118 ) , and their cousin Baldwin II ( 1118 – 1131 ) , expanded and secured the kingdom ' s borders , which encompassed roughly the same territory as modern - day Israel , Palestine , and Lebanon . During the kingdom ' s early decades , the population was swelled by pilgrims visiting the holiest sites of Christendom . Merchants from the Mediterranean city - states of Italy and France were eager to exploit the rich trade markets of the east . William ' s family probably originated in either France or Italy , since he was very familiar with both countries . His parents were likely merchants who had settled in the kingdom and were " apparently well - to - do " , although it is unknown whether they participated in the First Crusade or arrived later . William was born in Jerusalem around 1130 . He had at least one brother , Ralph , who was one of the city ' s burgesses , a non - noble leader of the merchant community . Nothing more is known about his family , except that his mother died before 1165 . As a child William was educated in Jerusalem , at the cathedral school in the Church of the Holy Sepulchre . The " scholaster " , or school - master , John the Pisan , taught William to read and write , and first introduced him to Latin . From the " Historia " it is clear that he also knew French and possibly Italian , but there is not enough evidence to determine whether he learned Greek , Persian , and Arabic , as is sometimes claimed . Around 1145 William went to Europe to continue his education in the schools of France and Italy , especially in those of Paris and Bologna , " the two most important intellectual centers of twelfth - century Christendom . " These schools were not yet the official universities that they would become in the 13th century , but by the end of the 11th century both had numerous schools for the arts and sciences . They were separate from the cathedral schools , and were established by independent professors who were masters of their field of study . Students from all over Europe gathered there to hear lectures from these masters . William studied liberal arts and theology in Paris and Orléans for about ten years , with professors who had been students of Thierry of Chartres and Gilbert de la Porrée . He also spent time studying under Robert of Melun and Adam de Parvo Ponte , among others . In Orléans , one of the pre - eminent centres of classical studies , he read ancient Roman literature ( known simply as " the Authors " ) with Hilary of Orléans , and learned mathematics ( " especially Euclid " ) with William of Soissons . For six years , he studied theology with Peter Lombard and Maurice de Sully . Afterwards , he studied civil law and canon law in Bologna , with the " Four Doctors " , Hugo de Porta Ravennate , Bulgarus , Martinus Gosia , and Jacob de Boraigne . William ' s list of professors " gives us almost a who ' s who of the grammarians , philosophers , theologians , and law teachers of the so - called Twelfth - Century Renaissance " , and shows that he was as well - educated as any European cleric . His contemporary John of Salisbury had many of the same teachers . Religious and political life in Jerusalem . The highest religious and political offices in Jerusalem were usually held by Europeans who had arrived on pilgrimage or crusade . William was one of the few natives with a European education , and he quickly rose through the ranks . After his return to the Holy Land in 1165 , he became canon of the cathedral at Acre . In 1167 he was appointed archdeacon of the cathedral of Tyre by Frederick de la Roche , archbishop of Tyre , with the support of King Amalric I . Amalric had come to power in 1164 and had made it his goal to conquer Egypt . Egypt had been invaded by King Baldwin I fifty years earlier , and the weak Fatimid Caliphate was forced to pay yearly tribute to Jerusalem . Amalric turned towards Egypt because Muslim territory to the east of Jerusalem had fallen under the control of the powerful Zengid sultan Nur ad - Din . Nur ad - Din had taken control of Damascus in 1154 , six years after the disastrous siege of Damascus by the Second Crusade in 1148 . Jerusalem could now expand only to the southwest , towards Egypt , and in 1153 Ascalon , the last Fatimid outpost in Palestine , fell to the crusaders . Nur ad - Din , however , also wished to acquire Egypt , and sent his army to hinder Amalric ' s plans . This was the situation in the east when William returned from Europe . In 1167 Amalric married Maria Comnena , grand - niece of Byzantine emperor Manuel I Comnenus , and in 1168 the king sent William to finalize a treaty for a joint Byzantine - crusader campaign against Egypt . The expedition , Amalric ' s fourth , was the first with support from the Byzantine navy . Amalric , however , did not wait for the fleet to arrive . He managed to capture Damietta , but within a few years he was expelled from Egypt by one of Nur ad - Din ' s generals , Saladin , who would later become Jerusalem ' s greatest threat . Meanwhile , William continued his advancement in the kingdom . In 1169 he visited Rome , possibly to answer accusations made against him by Archbishop Frederick , although if so , the charge is unknown . It is also possible that while Frederick was away on a diplomatic mission in Europe , a problem within the diocese forced William to seek the archbishop ' s assistance . On his return from Rome in 1170 he may have been commissioned by Amalric to write a history of the kingdom . He also became the tutor of Amalric ' s son and heir , Baldwin IV . When Baldwin was thirteen years old , he was playing with some children , who were trying to cause each other pain by scratching each other ' s arms . " The other boys gave evidence of pain by their outcries , " wrote William , " but Baldwin , although his comrades did not spare him , endured it altogether too patiently , as if he felt nothing . . . It is impossible to refrain from tears while speaking of this great misfortune . " William inspected Baldwin ' s arms and recognized the possible symptoms of leprosy , which was confirmed as Baldwin grew older . Amalric died in 1174 , and Baldwin IV succeeded him as king . Nur ad - Din also died in 1174 , and his general Saladin spent the rest of the decade consolidating his hold on both Egypt and Nur ad - Din ' s possessions in Syria , which allowed him to completely encircle Jerusalem . The subsequent events have often been interpreted as a struggle between two opposing factions , a " court party " and a " noble party . " The " court party " was led by Baldwin ' s mother , Amalric ' s first wife Agnes of Courtenay , and her immediate family , as well as recent arrivals from Europe who were inexperienced in the affairs of the kingdom and were in favour of war with Saladin . The " noble party " was led by Raymond III of Tripoli and the native nobility of the kingdom , who favoured peaceful co - existence with the Muslims . This is the interpretation offered by William himself in the " Historia " , and it was taken as fact by later historians . Peter W . Edbury , however , has more recently argued that William must be considered extremely partisan as he was naturally allied with Raymond , who was responsible for his later advancement in political and religious offices . The accounts of the 13th - century authors who continued the " Historia " in French must also be considered suspect , as they were allied to Raymond ' s supporters in the Ibelin family . The general consensus among recent historians is that although there was a dynastic struggle , " the division was not between native barons and newcomers from the West , but between the king ' s maternal and paternal kin . " Miles of Plancy briefly held the regency for the underaged Baldwin IV . Miles was assassinated in October 1174 , and Raymond III was soon appointed to replace him . Raymond named William chancellor of Jerusalem , as well as archdeacon of Nazareth , and on 6 June 1175 , William was elected archbishop of Tyre to replace Frederick de la Roche , who had died in October 1174 . William ' s duties as chancellor probably did not take up too much of his time ; the scribes and officials in the chancery drafted documents and it may not have even been necessary for him to be present to sign them . Instead he focused on his duties as archbishop . In 1177 he performed the funeral services for William of Montferrat , husband of Baldwin IV ' s sister Sibylla , when the patriarch of Jerusalem , Amalric of Nesle , was too sick to attend . In 1179 , William was one of the delegates from Jerusalem and the other crusader states at the Third Lateran Council ; among the others were Heraclius , archbishop of Caesarea , Joscius , bishop of Acre and William ' s future successor in Tyre , the bishops of Sebastea , Bethlehem , Tripoli , and Jabala , and the abbot of Mount Sion . Patriarch Amalric and Patriarch of Antioch Aimery of Limoges were unable to attend , and William and the other bishops did not have sufficient weight to persuade Pope Alexander III of the need for a new crusade . William was , however , sent by Alexander as an ambassador to Emperor Manuel , and Manuel then sent him on a mission to the Principality of Antioch . William does not mention exactly what happened during these embassies , but he probably discussed the Byzantine alliance with Jerusalem , and Manuel ' s protectorate over Antioch , where , due to pressure from Rome and Jerusalem , the emperor was forced to give up his attempts to restore a Greek patriarch . William was absent from Jerusalem for two years , returning home in 1180 . The patriarchal election of 1180 . During William ' s absence a crisis had developed in Jerusalem . King Baldwin had reached the age of majority in 1176 and Raymond III had been removed from the regency , but as a leper Baldwin could have no children and could not be expected to rule much longer . After the death of William of Montferrat in 1177 , King Baldwin ' s widowed sister Sibylla required a new husband . At Easter in 1180 , the two factions were divided even further when Raymond and his cousin Bohemond III of Antioch attempted to force Sibylla to marry Baldwin of Ibelin . Raymond and Bohemond were King Baldwin ' s nearest male relatives in the paternal line , and could have claimed the throne if the king died without an heir or a suitable replacement . Before Raymond and Bohemond arrived , however , Agnes and King Baldwin arranged for Sibylla to be married to a Poitevin newcomer , Guy of Lusignan , whose older brother Amalric of Lusignan was already an established figure at court . The dispute affected William , since he had been appointed chancellor by Raymond and may have fallen out of favour after Raymond was removed from the regency . When Patriarch Amalric died on 6 October 1180 , the two most obvious choices for his successor were William and Heraclius of Caesarea . They were fairly evenly matched in background and education , but politically they were allied with opposite parties , as Heraclius was one of Agnes of Courtenay ' s supporters . It seems that the canons of the Holy Sepulchre were unable to decide , and asked the king for advice ; due to Agnes ' influence , Heraclius was elected . There were rumours that Agnes and Heraclius were lovers , but this information comes from the partisan 13th - century continuations of the " Historia " , and there is no other evidence to substantiate such a claim . William himself says almost nothing about the election and Heraclius ' character or his subsequent patriarchate , probably reflecting his disappointment at the outcome . Death . William remained archbishop of Tyre and chancellor of the kingdom , but the details of his life at this time are obscure . The 13th - century continuator s claim that Heraclius excommunicated William in 1183 , but it is unknown why Heraclius would have done this . They also claim that William went to Rome to appeal to the Pope , where Heraclius had him poisoned . According to Peter Edbury and John Rowe , the obscurity of William ' s life during these years shows that he did not play a large political role , but concentrated on ecclesiastical affairs and the writing of his history . The story of his excommunication , and the unlikely detail that he was poisoned , were probably an invention of the Old French continuators . William remained in the kingdom and continued to write up until 1184 , but by then Jerusalem was internally divided by political factions and externally surrounded by the forces of Saladin , and " the only subjects that present themselves are the disasters of a sorrowing country and its manifold misfortunes , themes which can serve only to draw forth lamentations and tears . " His importance had dwindled with the victory of Agnes and her supporters , and with the accession of Baldwin V , infant son of Sibylla and William of Montferrat . Baldwin was a sickly child and he died the next year . In 1186 he was succeeded by his mother Sibylla and her second husband Guy of Lusignan , ruling jointly . William was probably in failing health by this point . Rudolf Hiestand discovered that the date of William ' s death was 29 September , but the year was not recorded ; whatever the year , there was a new chancellor in May 1185 and a new archbishop of Tyre by 21 October 1186 . Hans E . Mayer concluded that William died in 1186 , and this is the year generally accepted by scholars . William ' s foresight about the misfortunes of his country was proven correct less than a year later . Saladin defeated King Guy at the Battle of Hattin in 1187 , and went on to capture Jerusalem and almost every other city of the kingdom , except the seat of William ' s archdiocese , Tyre . News of the fall of Jerusalem shocked Europe and plans were made to send assistance . According to Roger of Wendover , William was present at Gisors in France in 1188 when Henry II of England and Philip II of France agreed to go on crusade : " Thereupon the king of the English first took the sign of the cross at the hands of the Archbishop of Rheims and William of Tyre , the latter of whom had been entrusted by our lord the pope with the office of legate in the affairs of the crusade in the western part of Europe . " Roger was however mistaken ; he knew that an unnamed archbishop of Tyre was present and assumed it must have been the William whose chronicle he possessed , although the archbishop in question was actually William ' s successor Joscius . Works . William reports that he wrote an account of the Third Council of the Lateran , which does not survive . He also wrote a history of the Holy Land from the time of Muhammad up to 1184 , for which he used Eutychius of Alexandria as his main source . This work seems to have been known in Europe in the 13th century but it also does not survive . August C . Krey thought William ' s Arabic sources may have come from the library of the Damascene diplomat Usama ibn Munqidh , whose library was looted by Baldwin III from a shipwreck in 1154 . Alan V . Murray , however , has argued that , at least for the accounts of Persia and the Turks in his chronicle , William relied on Biblical and earlier medieval legends rather than actual history , and his knowledge " may be less indicative of eastern ethnography than of western mythography . " Latin chronicle . William ' s great work is a Latin chronicle , written between 1170 and 1184 . It contains twenty - three books ; the final book , which deals with the events of 1183 and the beginning of 1184 , has only a prologue and one chapter , so it is either unfinished or the rest of the pages were lost before the whole chronicle began to be copied . The first book begins with the conquest of Syria by Umar in the seventh century , but otherwise the work deals with the advent of the First Crusade and the subsequent political history of the Kingdom of Jerusalem . It is arranged , but was not written , chronologically ; the first sections to be written were probably the chapters about the invasion of Egypt in 1167 , which are extremely detailed and were likely composed before the Fatimid dynasty was overthrown in 1171 . Much of the " Historia " was finished before William left to attend the Lateran Council , but new additions and corrections were made after his return in 1180 , perhaps because he now realized that European readers would also be interested in the history of the kingdom . In 1184 he wrote the Prologue and the beginning of the twenty - third book . William had access to the chronicles of the First Crusade , including Fulcher of Chartres , Albert of Aix , Raymond of Aguilers , Baldric of Dol , and the " Gesta Francorum " , as well as other documents located in the kingdom ' s archives . He used Walter the Chancellor and other now - lost works for the history of the Principality of Antioch . From the end of Fulcher ' s chronicle in 1127 , William is the only source of information from an author living in Jerusalem . For events that happened in William ' s own lifetime , he interviewed older people who had witnessed the events about which he was writing , and drew on his own memory . William ' s classical education allowed him to compose Latin superior to that of many medieval writers . He used numerous ancient Roman and early Christian authors , either for quotations or as inspiration for the framework and organization of the " Historia " . His vocabulary is almost entirely classical , with only a few medieval constructions such as " loricator " ( someone who makes armour , a calque of the Arabic " zarra " ) and " assellare " ( to empty one ' s bowels ) . He was capable of clever word - play and advanced rhetorical devices , but he was prone to repetition of a number of words and phrases . His writing also shows phrasing and spelling which is unusual or unknown in purely classical Latin but not uncommon in medieval Latin , such as : Literary themes and biases . Despite his quotations from Christian authors and from the Bible , William did not place much emphasis on the intervention of God in human affairs , resulting in a somewhat " secular " history . Nevertheless , he included much information that is clearly legendary , especially when referring to the First Crusade , which even in his own day was already considered an age of great Christian heroes . Expanding on the accounts of Albert of Aix , Peter the Hermit is given prominence in the preaching of the First Crusade , to the point that it was he , not Pope Urban II , who originally conceived the crusade . Godfrey of Bouillon , the first ruler of crusader Jerusalem , was also depicted as the leader of the crusade from the beginning , and William attributed to him legendary strength and virtue . This reflected the almost mythological status that Godfrey and the other first crusaders held for the inhabitants of Jerusalem in the late twelfth century . William gave a more nuanced picture of the kings of his own day . He claimed to have been commissioned to write by King Amalric himself , but William did not allow himself to praise the king excessively ; for example , Amalric did not respect the rights of the church , and although he was a good military commander , he could not stop the increasing threat from the neighbouring Muslim states . On a personal level , William admired the king ' s education and his interest in history and law , but also noted that Amalric had " breasts like those of a woman hanging down to his waist " and was shocked when the king questioned the resurrection of the dead . About Amalric ' s son Baldwin IV , however , " there was no ambiguity " . Baldwin was nothing but heroic in the face of his debilitating leprosy , and he led military campaigns against Saladin even while still underaged ; William tends to gloss over campaigns where Baldwin was not actually in charge , preferring to direct his praise towards the afflicted king rather than subordinate commanders . William ' s history can be seen as an " apologia " , a literary defense , for the kingdom , and more specifically for Baldwin ' s rule . By the 1170s and 1180s , western Europeans were reluctant to support the kingdom , partly because it was far away and there were more pressing concerns in Europe , but also because leprosy was usually considered divine punishment . William was famously biased against the Knights Templar , whom he believed to be arrogant and disrespectful of both secular and ecclesiastical hierarchies , as they were not required to pay tithes and were legally accountable only to the Pope . Although he was writing decades later , he is the earliest author to describe the actual foundation of the Templar order . He was generally favourable towards them when discussing their early days , but resented the power and influence they held in his own time . William accused them of hindering the Siege of Ascalon in 1153 ; of poorly defending a cave - fortress in 1165 , for which twelve Templars were hanged by King Amalric ; of sabotaging the invasion of Egypt in 1168 ; and of murdering Assassin ambassadors in 1173 . Compared to other Latin authors of the twelfth century , William is surprisingly favourable to the Byzantine Empire . He had visited the Byzantine court as an official ambassador and probably knew more about Byzantine affairs than any other Latin chronicler . He shared the poor opinion of Alexius I Comnenus that had developed during the First Crusade , although he was also critical of some of the crusaders ' dealings with Alexius . He was more impressed by Alexius ' son John II Comnenus ; he did not approve of John ' s attempts to bring the crusader Principality of Antioch under Byzantine control , but John ' s military expeditions against the Muslim states , the common enemy of both Greeks and Latins , were considered admirable . Emperor Manuel , whom William met during his visits to Constantinople , was portrayed more ambivalently , much like King Amalric . William admired him personally , but recognized that the Empire was powerless to help Jerusalem against the Muslim forces of Nur ad - Din and Saladin . William was especially disappointed in the failure of the joint campaign against Egypt in 1169 . The end of the " Historia " coincides with the massacre of the Latins in Constantinople and the chaos that followed the coup of Andronicus I Comnenus , and in his description of those events , William was certainly not immune to the extreme anti - Greek rhetoric that was often found in Western European sources . As a medieval Christian author William could hardly avoid hostility towards the kingdom ' s Muslim neighbours , but as an educated man who lived among Muslims in the east , he was rarely polemical or completely dismissive of Islam . He did not think Muslims were pagans , but rather that they belonged to a heretical sect of Christianity and followed the teachings of a false prophet . He often praised the Muslim leaders of his own day , even if he lamented their power over the Christian kingdom ; thus Muslim rulers such as Mu ' in ad - Din Unur , Nur ad - Din , Shirkuh , and even Jerusalem ' s ultimate conqueror Saladin are presented as honourable and pious men , characteristics that William did not bestow on many of his own Christian contemporaries . Circulation of the chronicle . After William ' s death the " Historia " was copied and circulated in the crusader state s and was eventually brought to Europe . In the 13th century , James of Vitry had access to a copy while he was bishop of Acre , and it was used by Guy of Bazoches , Matthew Paris , and Roger of Wendover in their own chronicles . However , there are only ten known manuscripts that contain the Latin chronicle , all of which come from France and England , so William ' s work may not have been very widely read in its original form . In England , however , the " Historia " was expanded in Latin , with additional information from the " Itinerarium Regis Ricardi " , and the chronicle of Roger Hoveden ; this version was written around 1220 . It is unknown what title William himself gave his chronicle , although one group of manuscripts uses " Historia rerum in partibus transmarinis gestarum " and another uses " Historia Ierosolimitana " . The Latin text was printed for the first time in Basel in 1549 by Nicholas Brylinger ; it was also published in the " Gesta Dei per Francos " by Jacques Bongars in 1611 and the " Recueil des historiens des croisades " ( RHC ) by Auguste - Arthur Beugnot and Auguste Le Prévost in 1844 , and Bongars ' text was reprinted in the " Patrologia Latina " by Jacques Paul Migne in 1855 . The now - standard Latin critical edition , based on six of the surviving manuscripts , was published as " Willelmi Tyrensis Archiepiscopi Chronicon " in the " Corpus Christianorum " in 1986 , by R . B . C . Huygens , with notes by Hans E . Mayer and Gerhard Rösch . The RHC edition was translated into English by Emily A . Babcock and August C . Krey in 1943 as " A History of Deeds Done Beyond the Sea , " although the translation is sometimes incomplete or inexact . Old French translation . A translation of the " Historia " into Old French , made around 1223 , was particularly well - circulated and had many anonymous additions made to it in the 13th century . In contrast to the surviving Latin manuscripts , there are " at least fifty - nine manuscripts or fragments of manuscripts " containing the Old French translation . There are also independent French continuations attributed to Ernoul and Bernard le Trésorier . The translation was sometimes called the " Livre dou conqueste " ; it was known by this name throughout Europe as well as in the crusader Kingdom of Cyprus and in Cilician Armenia , and 14th - century Venetian geographer Marino Sanuto the Elder had a copy of it . The French was further translated into Spanish , as the " Gran Conquista de Ultramar " , during the reign of Alfonso the Wise of Castile in the late 13th century . The French version was so widespread that the Renaissance author Francesco Pipino translated it back into Latin , unaware that a Latin original already existed . A Middle English translation of the French was made by William Caxton in the 15th century . Modern assessment . William ' s neutrality as an historian was often taken for granted until the late twentieth century . August C . Krey , for example , believed that " his impartiality . . . is scarcely less impressive than his critical skill . " Despite this excellent reputation , D . W . T . C . Vessey has shown that William was certainly not an impartial observer , especially when dealing with the events of the 1170s and 1180s . Vessey believes that William ' s claim to have been commissioned by Amalric is a typical ancient and medieval " topos " , or literary theme , in which a wise ruler , a lover of history and literature , wishes to preserve for posterity the grand deeds of his reign . William ' s claims of impartiality are also a typical " topos " in ancient and medieval historical writing . His depiction of Baldwin IV as a hero is an attempt " to vindicate the politics of his own party and to blacken those of its opponents . " As mentioned above , William was opposed to Baldwin ' s mother Agnes of Courtenay , Patriarch Heraclius , and their supporters ; his interpretation of events during Baldwin ' s reign was previously taken as fact almost without question . In the mid twentieth century , Marshall W . Baldwin , Steven Runciman , and Hans E . Mayer were influential in perpetuating this point of view , although the more recent re - evaluations of this period by Vessey , Peter Edbury and Bernard Hamilton have undone much of William ' s influence . An often - noted flaw in the " Historia " is William ' s poor memory for dates . " Chronology is sometimes confused , and dates are given wrongly " , even for basic information such as the regnal dates of the kings of Jerusalem . For example , William gives the date of Amalric ' s death as 11 July 1173 , when it actually occurred in 1174 . Despite his biases and errors , William " has always been considered one of the greatest medieval writers . " Steven Runciman wrote that " he had a broad vision ; he understood the significance of the great events of his time and the sequence of cause and effect in history . " Christopher Tyerman calls him " the historian ' s historian " , and " the greatest crusade historian of all , " and Bernard Hamilton says he " is justly considered one of the finest historians of the Middle Ages " . As the " Dictionary of the Middle Ages " says , " William ' s achievements in assembling and evaluating sources , and in writing in excellent and original Latin a critical and judicious ( if chronologically faulty ) narrative , make him an outstanding historian , superior by medieval , and not inferior by modern , standards of scholarship . "