Battle of the Olive Grove of Koundouros The Battle of the Olive Grove of Koundouros or Koundouras took place in the spring of 1205 , in Messinia , Peloponnese , between the Franks and the Greeks , resulting in a victory of the Frankish knights and the collapse of the local resistance . In 1204 , Constantinople , the capital city of the Byzantine Empire was taken by the Crusaders of the Fourth Crusade and the Republic of Venice . This led to the collapse of the Byzantine Empire and the establishment of the Latin Empire . Meanwhile , a Crusader force of between 500 and 700 knights under the command of William of Champlitte and Geoffrey I of Villehardouin advanced into the Peloponnese to deal with Byzantine resistance . In the Olive Grove of Koundouros in Messenia , they confronted an army of around 5 , 000 Peloponnesian Greeks under the command of Michael I Ducas . In the ensuing battle , the Crusaders emerged victorious , forcing the Byzantines to retreat and crushing resistance in the Peloponnese . This battle paved the way for the foundation of the Principality of Achaea . Background . The army of the Fourth Crusade conquered Constantinople on 12 April 1204 . One of the main leaders of the crusade , Boniface of Montferrat , having lost the opportunity to become Emperor , went on to found the Kingdom of Thessalonica . That autumn , William of Champlitte followed him to Thessalonica but then continued south until he reached the Morea . There he was joined by Geoffrey I Villehardouin , who sailed to Modon ( Methoni ) on his way back from Palestine . In charge of around a hundred knights and several soldiers , Champlitte and Villehardouin campaigned together to conquer Morea . They initially captured Methoni with the support of John Kantakouzenos . They occupied the main cities of the western Peloponnese while meeting little resistance . The Greeks of Lakonia , Arkadia and Argolis , under Michael I Komnenos Doukas , who at the time was the Byzantine governor of the theme of the Peloponnese , and Michael Kantakouzenos , the son of the then - deceased John Kantakouzenos , tried to stop the Franks at the Olive Grove of Koundouros , near Koroni . Primary sources . The battle is described in two original texts , " The Chronicle of the Conquest of Constantinople " , by Geoffrey of Villehardouin , written around 1207 – 1212 AD , and " The Chronicle of Morea " , written around 1300 . Both texts are written from the point of view of the conquerors . The first was written by the uncle of one of the two commanders who won the battle . The second was probably written by a person born from a mixed French - Greek marriage , since his attitude throughout the text is that of admiration for the Franks and contempt of the locals . Description of the battle . According to the " Chronicle of the Morea " , the Franks had 700 men , while the " Romans " ( Byzantine Greeks ) had 4000 men , mounted and unmounted . Geoffrey of Villehardouin , uncle of Geoffrey I , in his " Chronicle " , states that the army of Michael I numbered 5000 men and that of the Franks 500 . In any case , despite being outnumbered , the Franks won the battle . The resistance of the Greeks was paralyzed and all the castles and cities of the Peloponnese fell one after the other . Michael I fled to Epirus to establish the Despotate of Epirus . The exact location of the olive grove of Koundouros in Messenia is unknown ; Geoffrey of Villehardouin mentions that it was one day ' s distance from the castle of " Modon " ( Methoni ) , locating it somewhere in the Messenian plain , which is full of olive groves even today . In the " Chronicle of the Morea " , apart from the owner ' s name ( Kountouras ) , a location name is also indicated : Kepeskianous ( Κηπησκιάνους ) , for which there is no information nor any contemporary name . In Geoffrey ' s own account : " So William of Champlitte and Geoffry of Villehardouin " [ the nephew ] " departed from the host , and took with them about a hundred knights , and a great number of mounted sergeants , and entered into the land of Morea , and rode onwards till they came to the city of Modon . Michael heard that they were in the land with so few people , and he collected together a great number of people , a number that was marvellous , and he rode after them as one thinking they were all no better than prisoners , and in his hand . And when they heard tell that he was coming , they refortified Modon , where the defences had long since been pulled down , and there left their baggage , and the lesser folk . Then they rode out a day ' s march , and ordered their array with as many people as they had . But the odds seemed too great , for they had no more than five hundred men mounted , whereas on the other part there were well over five thousand . But events happen as God pleases ; for our people fought with the Greeks and discomfited and conquered them . And the Greeks lost very heavily , while those on our side gained horses and arms enough , and other goods in very great plenty , and so returned very happy , and very joyously , to the city of Modon " . In the " Chronicle of the Morea " , the battle is described in verses 1720 – 1738 : " / they heard and they learned that the Franks had come , " / and that they walked through the villages and took the gains of war " / and they said and they thought they had been harmed " / Over there they were drawn , they call it Kepescianous ' / where they name it the olive grove of Kountouras " / They were four thousand , on foot and mounted " / The Franks , though , when they learned it from the Romans " / since they were together with them and they knew the place " / there they drew them , they came and they found them " / and war they gave the Franks and the Romans . " / And the Franks were not , on foot and mounted , " / but just seven hundred , that many they thought . " / Eagerly did the Romans start the war , " / because they saw them few , but later they were sorry . " / Why shall I tell you a lot and what do we care ? " / The war , they won , then , those Franks " / they slaughtered them all , a few did escape " / That was the only war the Romans made " / during the time that the Franks won the Morea . Aftermath . The Battle of the Olive Grove of Kountoura was decisive for the conquest of the Peloponnese by the Franks . After their victory , there was no serious threat against them in the Morea . In Andravida , they were received by the people and Church . The only resistance met later was defensive , by Leo Sgouros , guarding the castles of Nafplion and Acrocorinth . William of Champlitte was able to build upon his victories by forming the Principality of Achaia , a Frankish state comprising most of the Peloponnese except for the Venetian cities on the coast .