Constantine I of Greece Constantine I ( , " Konstantínos Αʹ , Vasiléfs ton Ellínon " ; – 11 January 1923 ) was King of Greece from 1913 to 1917 and from 1920 to 1922 . He was commander - in - chief of the Hellenic Army during the unsuccessful Greco - Turkish War of 1897 and led the Greek forces during the successful Balkan Wars of 1912 – 1913 , in which Greece won Thessaloniki and doubled in area and population . He succeeded to the throne of Greece on 18 March 1913 , following his father ' s assassination . His disagreement with Eleftherios Venizelos over whether Greece should enter World War I led to the National Schism . Constantine forced Venizelos to resign twice , but in 1917 he left Greece , after threats of the Entente forces to bombard Athens ; his second son , Alexander , became king . After Alexander ' s death , Venizelos ' defeat in the 1920 legislative elections , and a plebiscite in favor of his return , Constantine was reinstated . He abdicated the throne for the second and last time in 1922 , when Greece lost the Greco - Turkish War of 1919 - 1922 , and was succeeded by his eldest son , George II . Constantine died in exile four months later , in Sicily . Early life . Born on 2 August 1868 in Athens , Constantine was the eldest son of King George I and Queen Olga of Greece . His birth was met with an immense wave of enthusiasm : the new heir apparent to the throne was the first Greek - born royal . As the ceremonial cannon on Lycabettus Hill fired the Royal salute , huge crowds gathered outside the Palace shouting what they thought should rightfully be the newborn prince ' s name : " Constantine " . This was not only the name of his maternal grandfather , Grand Duke Konstantin Romanov of Russia , but also the name of the " King who would reconquer Constantinople " , the future " Constantine " XII " , legitimate successor to the Emperor Constantine XI Palaiologos " , according to popular legend . Upon his birth , he was created Duke of Sparta . This resulted in a heated dispute in Parliament , since the constitution neither allowed nor recognized any titles of nobility for Greek citizens , but the purely titular dignity was eventually awarded . He was inevitably christened " Constantine " ( Greek : Κωνσταντῖνος , " Kōnstantīnos " ) on 12 August , and his official style was the " Diádochos " ( Διάδοχος , Crown Prince , literally : " Successor " ) . An additional nickname adopted mainly by the royalists for Constantine was " the son of the eagle " ( " ο γιός του αητού " ) . The most prominent university professors of the time were handpicked to tutor the young Crown Prince : Ioannis Pantazidis taught him Greek literature ; Vasileios Lakonas mathematics and physics ; and Constantine Paparrigopoulos history , infusing the young prince with the principles of the " Megali Idea " . On 30 October 1882 he enrolled in the Hellenic Military Academy . After graduation he was sent to Berlin for further military education , and served in the German Imperial Guard . Constantine also studied political science and business in Heidelberg and Leipzig . In 1890 he became a Major General , and assumed command of the 3rd Army Headquarters ( " Γ ' Αρχηγείον Στρατού " ) in Athens . Confrontations with Trikoupis . In January 1895 , Constantine caused political turmoil when he ordered army and gendarmerie forces to break up a street protest against tax policy . Constantine had previously addressed the crowd and advised them to submit their grievances to the government . Prime Minister Charilaos Trikoupis asked the King to recommend that his son avoid such interventions in politics without prior consultation with the government . King George responded that the Crown Prince was , in dispersing protesters , merely obeying military orders , and that his conduct lacked political significance . The incident caused a heated debate in Parliament , and Trikoupis finally resigned as a result . In the following elections Trikoupis was defeated , and the new Prime Minister , Theodoros Deligiannis , seeking to downplay hostility between government and the Palace , regarded the matter closed . The organization of the first modern Olympics in Athens was another issue which caused a Constantine - Trikoupis confrontation , with Trikoupis opposed to hosting the Games . After Deligiannis ' electoral victory over Trikoupis in 1895 , those who favored a revival of the Olympic Games , including the Crown Prince , prevailed . Subsequently , Constantine was instrumental in the organization of the 1896 Summer Olympics ; according to Pierre de Coubertin , in 1894 " the Crown Prince learned with great pleasure that the Games will be inaugurated in Athens . " Coubertin assured that " the King and the Crown Prince will confer their patronage on the holding of these Games . " Constantine later conferred more than that ; he eagerly assumed the presidency of the 1896 organizing committee . At the Crown Prince ' s request , wealthy businessman George Averoff agreed to pay approximately one million drachmas to fund the restoration of the Panathinaiko Stadium in white marble . Greco - Turkish War and aftermath . Constantine was the commander - in - chief of the Greek Army in the Greco - Turkish War of 1897 , which ended in a humiliating defeat . In its aftermath , the popularity of the monarchy fell , and calls were raised in the army for reforms and the dismissal of the royal princes , and especially Constantine , from their command posts in the armed forces . The simmering dissent culminated in the Goudi coup in August 1909 . In its aftermath , Constantine and his brothers were dismissed from the armed forces , only to be reinstated a few months later by the new Prime Minister , Eleftherios Venizelos , who was keen on gaining the trust of King George . Venizelos was ingenious in his argumentation : " All Greeks are rightly proud to see their sons serve in the army , and so is the King " . What was left unsaid was that the royal princes ' commands were to be on a very tight leash . Balkan Wars . Overview . Turkish planning was foreseeing a two - prong Greek attack east and west of the impassable Pindus mountain range , and they accordingly allotted their resources , equally divided , on a defensive posture in order to fortify the approaches to Ioannina , capital of Epirus , and the mountain passes leading from Thessaly to Macedonia . This was a grave error . The war plan by Venizelos and the General Staff called for a rapid advance with overwhelming force towards Thessaloniki with its vitally important harbor . A minute force of little more than a division proper , just enough to forestall a possible Turkish redeployment eastwards , was to be sent west as the " Army of Epirus " , while the bulk of the army and artillery would embark on what would later be called " blitzkrieg " tactics against the Turks in the east . In the event the Greek plan worked brilliantly : advancing on foot , the Greeks defeated the Turks soundly twice , and were in Thessaloniki within 4 weeks . The Greek plan for overwhelming attack and speedy advance hinged upon another factor : should the Greek Navy succeed in blockading the Turkish fleet within the Straits , any Turkish reinforcements from Asia would have no way of reaching Europe fast . Turkey would be slow to mobilize , and even when the masses of loyal troops raised in Asia were ready , they could go no further than the outskirts of Istanbul , fighting the Bulgarians in brutal trench warfare . With the Bulgarians directing the bulk of their force towards Constantinople , capture of Thessaloniki would ensure that the railway axis between these two main cities was lost to the Turks , who would then suffer total loss of logistics and supplies and severe impairment of command and control capability . The Turks would be hard placed to recruit locals , as their loyalties would be liable to lie with the Balkan Allies . Ottoman armies in Europe would be quickly cut off and their loss of morale and operational capability would lead them toward a quick surrender . Macedonian Front . Previously the Inspector General of the Army , Constantine was appointed commander - in - chief of the Greek " Army of Thessaly " when the First Balkan War broke out in October 1912 . He led the Army of Thessaly to victory at Sarantaporos . At this point , his first clash with Venizelos occurred , as Constantine desired to press north , towards Monastir , where the bulk of the Ottoman army lay , and where the Greeks would rendezvous their Serb allies . Venizelos , on the other hand , demanded that the army capture the strategic port city of Thessaloniki , the capital of Macedonia , with extreme haste , so as to prevent its fall to the Bulgarians . The dispute resulted in a heated exchange of telegrams . Venizelos notified Constantine that " . . . political considerations of the utmost importance dictate that Thessaloniki be taken as soon as possible " . After Constantine impudently cabled : " The army will not march on Thessaloniki . My duty calls me towards Monastir , unless you forbid me " , Venizelos was forced to pulled rank . As Prime Minister and War Minister , he outranked Constantine and his response was famously three - words - long , a crisp military order to be obeyed forthwith : " I forbid you " . Constantine was left with no choice but to turn east , and after defeating the Ottoman army at Giannitsa , he accepted the surrender of the city of Thessaloniki and of its Ottoman garrison on 27 October ( O . S . ) , less than 24 hours before the arrival of Bulgarian forces who hoped to capture the city first . The capture of Thessaloniki against Constantine ' s whim proved a crucial achievement : the pacts of the Balkan League had provided that in the forthcoming war against the Ottoman Empire , the four Balkan allies would provisionally hold any ground they took from the Turks , without contest from the other allies . Once an armistice was declared , then facts on the ground would be the starting point of negotiations for the final drawing of the new borders in a forthcoming peace treaty . With the vital port firmly in Greek hands , all the other allies could hope for was a customs - free dock in the harbor . Epirus Front . In the meantime , operations in the Epirus front had stalled : against the rough terrain and Ottoman fortifications at Bizani , the small Greek force could not make any headway . With operations in Macedonia complete , Constantine transferred the bulk of his forces to Epirus , and assumed command . After lengthy preparations , the Greeks broke through the Ottoman defences in the Battle of Bizani and captured Ioannina and most of Epirus up into what is today southern Albania ( Northern Epirus ) . These victories dispelled the tarnish of the 1897 defeat , and raised Constantine to great popularity with the Greek people . Accession to the Throne and Second Balkan War . At that point , tragedy struck : George I was assassinated in Thessaloniki by an anarchist , Alexandros Schinas , on 18 March 1913 , and Constantine succeeded to the throne . In the meantime , tensions between the Balkan allies grew , as Bulgaria claimed Greek and Serbian - occupied territory . In May , Greece and Serbia concluded a secret defensive pact aimed at Bulgaria . On 16 June , the Bulgarian army attacked their erstwhile allies , but were soon stopped . King Constantine again led the Greek Army in its counterattack in the battles of Kilkis - Lahanas and the Kresna Gorge . He was keen to go for the jugular , Sofia . In the meantime the Bulgarian army has started to disintegrate : beset by defeat in the hands of Greeks and Serbs , they were suddenly faced with a surprising Turkish counterattack with fresh Asian troops finally ready , while the Romania ns advanced south , demanding Southern Dobrudja as a compensation to the overreaching Bulgarians . Bulgaria had to sue for peace , agreed to an armistice and entered negotiations in Bucharest . The victories in the second war gave a further boost to Constantine ' s popularity , with him being widely acclaimed as " Bulgar - slayer " , in imitation of the Byzantine emperor Basil II . On the initiative of Prime Minister Venizelos , Constantine was also awarded the rank and baton of a Field Marshal . World War I and the National Schism . The widely - held view of Constantine I as a " German sympathiser " owes much to Allied and Venizelist war - time propaganda directed against the King . Constantine rebuffed Kaiser Wilhelm who in 1914 pressed him to bring Greece into the war on the side of Austria and Germany . Constantine offended British and French interests by blocking efforts by Prime Minister Venizelos to bring Greece into the war on the side of the Allies . Constantine ' s insistence on neutrality was based on his judgement that it was the best policy for Greece . Admiral Mark Kerr , who was Commander - in - Chief of the Royal Hellenic Navy in the early part of World War I and later Commander - in - Chief of the British Adriatic Squadron , wrote in 1920 : " The persecution of King Constantine by the press of the Allied countries , with some few good exceptions , has been one of the most tragic affairs since the Dreyfus case . " [ Abbott , G . F . ( 1922 ) ' Greece and the Allies 1914 - 1922 ' ] Although Venizelos , with British and French support , forced Constantine from the Greek throne in 1917 he remained popular with parts of the Greek people , as shown by the overwhelming vote for his return in the December 1920 plebescite . In the aftermath of the victorious Balkan Wars , Greece was in a state of euphoria . Her territory and population had doubled and , under the dual leadership of Constantine and Venizelos , her future seemed bright . This state of affairs was not bound to last long , however . When World War I broke out , Constantine was faced with the difficulty of determining where Greece ' s support lay . His own sympathies lay with Imperial Germany ruled by his wife ' s brother , the Kaiser . Sophie , his queen , was popularly thought to support her brother as well , but it seems that she was actually pro - British ; like her father the late Kaiser Frederick , Sophie was heavily influenced by her mother , the British - born Victoria . Venizelos was fervently pro - Entente , having established excellent rapport with the British and French echelons of power . He also was keenly aware that a maritime country like Greece could not , and should not , antagonise the Entente , the dominant naval powers in the Mediterranean . This latter point at least came across to the king , no matter where his personal sympathies lay . He finally chose a policy of neutrality . The bold , insubordinate general of a few years before now seemed content to risk nothing and would possibly settle for as much after the war was over . Unable to impose unconstitutionally his will upon the lawfully elected government , he chose to neutralise it for the time being . Constantine ' s sympathies for Germany were made manifest during the Allies ' disastrous landing on Gallipoli . Despite support for Venizelos among the people and his clear majority in Parliament , Constantine opposed Venizelos ' s increasing support for the Allies . When Bulgaria attacked Serbia , with whom Greece had a treaty of alliance , Venizelos again urged the King to allow Greece ' s entry into the war , and permitted Entente forces to disembark in Thessaloniki in preparation for a common campaign over the king ' s objections . After Constantine refused again to support Greece ' s entry on the side of the Allies , however , Venizelos resigned , and Constantine appointed Alexandros Zaimis in his place , at the head of a short - lived coalition government . In July 1916 , arsonists set fire to the forest surrounding the summer palace at Tatoi , in what was popularly seen as a sign of dissatisfaction with the king ' s policy of neutrality . Although injured in the escape , the king and his family managed to flee to safety . The flames spread quickly in the dry summer heat , and sixteen people were killed . In May and August 1916 , Constantine and General Ioannis Metaxas ( future dictator ) allowed parts of eastern Macedonia to be occupied , without opposition , by the Central Powers . The country seethed with rage and in August 1916 , an Entente - supported Venizelist revolt broke out in Thessaloniki . There , Venizelos established a provisional revolutionary government , which declared war on the Central Powers . With civil war apparently imminent , Constantine sought firm German promises of naval , military and economic assistance - without success . Gradually , and with Allied support , Venizelos gained control of half the country - significantly , most of the " New Lands " won during the Balkan Wars . This cemented the " National Schism " , a division of Greek society between Venizelists and anti - Venizelist monarchists , which was to have repercussions in Greek politics until past World War II . Early in 1917 , the Venizelist Government of National Defence ( based in Thessaloniki ) took control of Thessaly . In the face of Venizelist and Anglo - French pressure , King Constantine left the country for Switzerland on 11 June 1917 ; his second - born son Alexander became king in his place . The Allied Powers were opposed to Constantine ' s firstborn son George becoming King , as he had served in the German army before the war and identified with his father ' s pro - German policies . Restoration and disaster . Constantine ' s younger son , King Alexander , died on 25 October 1920 , after a freak accident : he was strolling with his dogs in the royal menagerie , when they attacked a monkey . Rushing to save the poor animal , the king was bitten by the monkey and what seemed like a minor injury turned to septicemia . He died a few days later . The following month Venizelos suffered a surprising defeat in a general election . Greece had at this point been at war for eight continuous years : World War I had come and gone , yet no sign of an enduring peace was near . All young men had been fighting and dying for years , lands lay fallow for lack of hands to cultivate them , and the country , morally exhausted , was at the brink of physical exhaustion . The pro - royalist parties promised peace and prosperity under the victorious Field Marshal of the Balkan Wars , he who knew of the soldier ' s plight because he had fought next to him and shared his ration . Following a plebiscite in which nearly 99 % of votes were cast in favor of his return , Constantine returned as king on 19 December 1920 . This caused great dissatisfaction not only to the newly liberated populations in Asia Minor , but also to the Great Powers who opposed the return of Constantine . Within two years the king ' s new - found popularity was lost again . The inherited ongoing Asia Minor Campaign against Turkey proved disastrous for the Greeks . An ill - conceived plan to go for the jugular again , Kemal ' s new capital of Ankara , deep in barren Anatolia where no Greek lived , succeeded enough only to raise some faint and ill - fated hopes . The Turks eventually broke the overstretched Greek front and routed the Greek army through Anatolia to the shore , burning Smyrna . Following an army revolt , Constantine abdicated the throne again on 27 September 1922 and was succeeded by his eldest son , George II . Second Exile and death . He spent the last four months of his life in exile in Italy and died in 1923 at Palermo , Sicily . His queen , Sophie of Prussia , was never allowed back in Greece . A life and reign that had started under the brightest of auspices ended in ruin . Marriage and issue . Constantine was married to Princess Sophie of Prussia , a granddaughter of Queen Victoria and sister of Kaiser Wilhelm II . The couple were married on 27 October 1889 in Athens . They had six children : Michalopoulos , Dimitris , " Constantine XII , King of the Hellenes . An outline of his personality and times " , " Parnassos " , vol . 46 , pp . 355 – 360 .