 Complete the following phrase:  The 14th century was tumultuous: the area was pillaged by Karasid Turks in 1331, and captured by the Serbian ruler Stephen Dushan in 13434, when it became part of his Serbian Empire. It was recovered for Byzantium by John VI Kantakouzenos in 1350, but lost again to the Serbians soon after, becoming the domain of Radoslav Hlapen after 1358. With the 