Korone is a city in the southeast corner of Messenia in the Peloponnese. The city had civic status in late antiquity, and a fragment of Diocletian's Price Edict was discovered there. By the time of the Slavic invasions the site was probably strongly fortified. 
At some undetermined date the people of ancient Korone (modern Petalidi) moved to Asine, and the name was changed. By the early 9th century a bishop of Korone is attested as a suffragan of the archbishop of Patras. Like Methone, Korone profited from the pilgrimage traffic and the growth of east-west trade from the 11th century onward. After the Fourth Crusade Korone was first granted to Geoffrey I Villehardouin, who ceded it to Venice in 1209. Around 1300 it was under the authority of Monemvasia. The Greek peasants of the hinterland of Korone seem to have had a favorable status in comparison with their counterparts in the Morea: they could hold land, in addition to their unfree tenure (stasia) and could dispose of this land freely without recourse to the commune. The imposing fortress on the sea, although substantially rebuilt by Venice, is essentially Byzantine, probably to be assigned to the 6th-7th century. Within the fortress are the remains of a basilica, presumably of the same date. 


Oxford Dictionary of Byzantium