The forces of Michael VIII Palaiologos had…
1262 CE
The forces of Michael VIII Palaiologos had killed or captured most of the Latin nobles of the Principality of Achaea, including Prince William II of Villehardouin, at the Battle of Pelagonia in 1259.
William has agreed on release to hand over a number of fortresses in the southwestern part of the Morea peninsula.
He has also sworn an oath of allegiance to Michael, becoming his vassal and being honored by becoming godfather to one of Michael's sons and receiving the title and post of megas domestikos.
William is released in early 1262, and the forts of Monemvasia and Mystras, with the districts of Mani and Kinsterna, are handed over to the Greeks.
The agreement is bound to be of short duration, however: the establishment of a small province in the Morea is for Palaiologos but the first step towards reclaiming all of the peninsula, and William likewise is involved in the Latin efforts to counter the emperor and regain Constantinople.
William settles his differences with the Venetians over Negroponte soon after his return to the Morea, and negotiates with them and the Pope for joint action against Palaiologos.
Pope Urban IV in July nullifies William's oaths to the emperor, and appeals to the Western princes for aid against the "schismatic" Greeks.