The fortress of Tomorr in the early 14th century is attested as "Timoro(n)" under Byzantine control. In 1337, the Albanian tribes which lived in the areas of Belegrita (the region of Mt. Tomorr near Berat) and Kanina rose in rebellion, and seized the fortress of Tomorr. There is little detail about the rebellion in primary sources. John VI Kantakouzenos mentions that the Albanians in those areas rebelled despite the privileges which Andronikos III Palaiologos had given them a few years earlier. These events marked the movement of these Albanian tribes into Epirus for the first time. Andronikos led an army mainly composed of Turkish mercenaries, and defeated the Albanians, killing many and taking prisoners. In 1345 (or maybe 1343) the town passed to the Serbian Empire. After its dissolution in 1355 Berat came under suzerainty of its former governor, John Komnenos Asen (1345-1363), Alexander Komnenos Asen (1363-1372) and Zeta of Balša II (1372-1385). In 1385 Berat was captured by the Ottomans, before the Battle of Savra. According to some sources, the Ottomans probably remained in Berat for some time with intention to use it as foothold to capture Valona. By 1396, the Albanian Muzaka family took over control of Berat which became the capital of the Principality of Berat. In 1417 Berat became a part of the Ottoman Empire. In 1455 Skanderbeg, a commander with an Albanian force of 14,000 and small number of Catalan soldiers unsuccessfully tried to capture Berat from an Ottoman force of 40,000.