Catalan Company The Catalan Company of the East ( , ) , officially the " Magnas Societas Catalanorum " , sometimes called the " Grand Company " and widely known as the Catalan Company , was a free company of mercenaries founded by Roger de Flor in the early 14th century . De Flor recruited soldiers left unemployed with the Peace of Caltabellotta in 1302 by the Crown of Aragon who opposed the French dynasty of Anjou . In 1303 de Flor offered the services of his Company to the Byzantine emperor Andronicus II Palaeologus and his son the Basileus Michael IX Palaeologus . The Byzantine Empire was under threat by the Turks who were invading Anatolia . Roger de Flor ' s offer was accepted by both Byzantium and by the Aragonese , rulers in Sicily and southern Italy , who were quite eager to rid themselves of unemployed and unruly soldiers . Roger de Flor departed with 39 galley s and transports carrying around 1 , 500 knights and 4 , 000 Almogavars , special foot soldiers employed mainly serving the kingdom ' s interests in the Mediterranean Sea , especially by the Crown of Aragon . Roger de Flor arrived in Constantinople with the help of king Frederick III of Sicily in 1303 , and married the niece of Andronicus , daughter of the Tsar of Bulgaria , and was named Grand Duke ( head of the fleet ) . Roger de Flor campaigned with his Company in Anatolia , defeating the Turks but also engaging in widespread violence and looting of the Byzantine inhabitants . By this point , the Catalans , who had recruited nearly 3000 Turkic horse into their ranks , were considered by the Byzantines to be little better than brigands and freebooters . The successes had inflated the already arrogant De Flor , leading him to entertain plans of establishing his own dominion in Anatolia . This put him at odds with the Byzantine Emperor , and the indiscipline of the Almogavars marked the end of Roger de Flor . On 30 April 1305 , he was slain along with 300 cavalry and 1 , 000 infantry by the Alans , another group of mercenaries at the service of the Emperor . Roger had been in Adrianopolis ( modern Edirne ) attending a banquet offered by Emperor Michael . The emperor later attacked Gallipoli attempting to conquer the city from the remnants of the Company under the command of Berenguer d ' Entença who had arrived with 9 Catalan galleys . The attack was unsuccessful , but it largely decimated the Company . Berenguer d ' Entença was captured by the Genoese shortly after , and later liberated . The Company had only 206 horsemen , 1 , 256 foot soldiers left and no clear leader when Emperor Michael attacked , trusting in his numerical superiority , only to be defeated in Battle of Apros in July 1305 . The Company proceeded to devastate the regions of Thrace and Macedonia for the next two years , including an attack on Mount Athos . Until recently no Catalans were allowed on the Athos peninsula by the Athonite monks . However in the past few years and following the payment of reparations by the Catalan government this situation has changed . The Company was a powerful asset in the political arena and Frederick III of Sicily tried to gain control over it . He assigned the Infante Ferdinand of Majorca to Gallipoli to become its Captain . However one of the leaders of the Company , Bernat de Rocafort opposed this move , and faced Berenguer d ' Entença , Ferran Ximenis d ' Arenós , and others who had accepted the Infante . The struggle ended with the departure of both the Infante and Ferran , and with Bernat de Rocafort becoming leader of the Company . The administrator , Ramon Muntaner also left and later wrote a chronicle about exploits of the Company . Bernat de Rocafort offered the Company ' s services to Charles of Valois to strengthen his claim to the Byzantine Empire and whom the Count of Barcelona had expelled from Sicily before founding the Company in a dynastic war for the Crown of Aragon . In 1309 , Thibault de Chepoy , the deputy of Charles of Valois , ended the leadership of Rocafort , arresting him and sending him to Naples where he died of hunger the same year . In 1310 Roger Deslaur then offered its service to Walter V of Brienne Duke of Athens and within a year it freed the duchy of its enemies , only to be betrayed by Brienne who refused to pay for its services . The Company avenged itself , defeating and killing Brienne in the Battle of Halmyros on the March 15 , 1311 , taking control of the duchy of Athens . Around this time , the Company also conquered the city of Thebes . In 1318 the Company expanded its power into Thessaly , taking control of the Duchy of Neopatria . The Catalan rule was to last until 1388 – 1390 when they were defeated by the Navarrese Company under Pedro de San Superano , Juan de Urtubia , and allied with the Florentines under Nerio I Acciaioli of Corinth . His descendants controlled them until 1456 when they were conquered by the Ottoman Empire . By that time , like many military enterprises , the Great Company had faded out of history . Notes . The early history of the Catalan Company was chronicled by Ramon Muntaner , a former member of the company , in his " Crònica " .