Battle of Neopatras The Battle of Neopatras was fought in the early 1270s between a Byzantine army besieging the city of Neopatras and the forces of John I Doukas , ruler of Thessaly . The battle was a rout for the Byzantine army , which was caught by surprise and defeated by a much smaller but more disciplined force . Background . In 1259 , the Empire of Nicaea , led by Michael VIII Palaiologos ( r . 1259 – 1282 ) , had achieved a great victory in the Battle of Pelagonia against a coalition of its major European foes , the Despotate of Epirus , the Kingdom of Sicily and the Principality of Achaia . This victory had in large measure been achieved through the defection of John Doukas , the illegitimate child of Michael II of Epirus . This victory enabled Palaiologos to consolidate his territories in Europe ; further , the weakening of Epirus and the Latin states allowed him carry out the reconquest of Constantinople in 1261 and to re - establish the Byzantine Empire , with himself as emperor . The Nicaean forces failed however to subdue Epirus : John Doukas quickly returned to his father ' s allegiance , and the local population remained loyal to Michael II . The Nicaeans were expelled from the area in 1259 , and then defeated and driven out from Thessaly as well in 1260 . In 1266 or 1268 , Michael II of Epirus died , and his possessions were divided among his sons : his eldest legitimate son , Nikephoros , inherited what remained of Epirus proper , while John , who had married the daughter of a local Vlach ruler of Thessaly ( " Great Wallachia " ) , received Thessaly with his capital at Neopatras . Both brothers were hostile to the restored Byzantine Empire , which aimed to reclaim their territories , and maintained close relations with the Latin states in southern Greece . Nevertheless , Michael VIII tried to attach them to him through dynastic marriages : Nikephoros was given his niece Anna Kantakouzene , while one of his nephews , Andronikos Tarchaneiotes , was wed to the daughter of John Doukas , who in addition received the light title of " sebastokrator " . Michael failed in his aim , however , as both , and particularly John , remained ill - disposed towards him . Following the deeply unpopular Union of the Churches in 1274 , the two even provided refuge for the many dissenters and critics of Michael ' s religious policies . Nevertheless , through the negotiations , the Act of Union and the submission of the Greek Orthodox Church to the See of Rome , Michael averted the danger of a concerted Latin attack on his state , and was free to move against his enemies . Immediately , he launched offensives against the Sicilian holdings in Albania , and against John Doukas in Thessaly . The battle . For the campaign against Thessaly ( the date is uncertain , most recent scholars favour 1272 / 1273 or 1274 / 1275 ) , Michael assembled a huge force , mostly mercenaries , which contemporary sources put , certainly with considerable exaggeration , at 30 , 000 ( Pachymeres speaks of 40 , 000 men , including the naval forces ) . These were placed under his own brother , the " despotes " John Palaiologos , and the general Alexios Kaballarios . This force was sent against Thessaly , and was to be aided by the Byzantine navy under the " protostrator " Alexios Doukas Philanthropenos , who was to attack the Latin principalities and prevent them from aiding John Doukas . Doukas was caught completely by surprise by the rapid advance of the imperial forces , and was bottled up with few men in his capital , Neopatras , which the Byzantines proceeded to lay siege to . Doukas , however , resorted to a ruse : he climbed down the walls of the fortress with a rope and , disguised as a groom , he managed to cross the Byzantine leaguer . After three days , he reached Thebes , where he requested the aid of John I de la Roche ( r . 1263 – 1280 ) , the Duke of Athens . The two rulers concluded a treaty of alliance , by which John de la Roche ' s brother and heir , William , would marry John Doukas ' s daughter Helen and receive the fortresses of Gravia , Siderokastron , Gardiki and Lamia as her dowry . In return , de la Roche gave Doukas 300 or 500 horsemen ( depending on the source ) with whom he returned quickly to Neopatras . The Byzantine force there had been considerably weakened , with several detachments sent off to capture other forts or plunder the region , and was furthermore unwieldy and not very cohesive , given the many races that served in it . According to the Venetian historian Marino Sanudo , when John Doukas and John de la Roche climbed a height and saw the huge Byzantine encampment , de la Roche uttered , in Greek , a phrase from Herodotus : " there are a lot of people here , but few men . " Indeed , the Byzantine troops panicked under the sudden attack of the smaller but disciplined Latin force , and broke completely when a Cuman contingent abruptly switched sides . Despite John Palaiologos ' s attempts to rally his forces , they fled and scattered . Aftermath . At the news of this success , the Latins became emboldened and assembled a fleet to attack the Byzantine fleet , which was anchored at Demetrias ( near modern Volos ) . Initially , the Latins made good progress , inflicting many casualties on the Byzantine crews . But just as victory seemed imminent , John Palaiologos arrived with reinforcements and turned the tide of the battle . Despite this victory , however , the " despotes " was shattered by the disaster of Neopatras : he resigned his post and died later the same year .