The Treaty of Sapienza was concluded in June 1209 between the Republic of Venice and the newly established Principality of Achaea, under Prince Geoffrey I of Villehardouin, concerning the partition of the Peloponnese (Morea) peninsula, conquered following the Fourth Crusade. By its terms, Venice, which had been accorded most of the Peloponnese in the Partitio Romaniae, recognized Villehardouin in possession of the entire peninsula except for the two forts of Modon and Coron, which came under Venetian control, and secured commercial and tax privileges in the Principality. The text of the treaty is also a valuable primary source for the early history of the Principality of Achaea.