Complete the following sentence: Familiarity with the Slavic element in the area led two brothers from Thessaloniki, Saints Cyril and Methodius, to be chosen to convert the Slavs to Christianity. ️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️ 1204, a short-lived Crusader realm, the Kingdom of Thessalonica, was established in the region. ️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️ ️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️ <unk> <unk> <unk> <unk>
Battle of Maritsa (1371), Byzantine rule was reestablished in eastern regions, including Serres. During the 1380s, the region was gradually conquered by the advancing Ottomans, with Serres holding out until 1383, and Thessaloniki until 1387. 1430 (during the last seven years of which the city was handed over to the Venetians), Thessaloniki and its immediate surrounding area returned to the Ottomans.