The Principality of Moravian Serbia (Serbian: Моравска Србија / Moravska Srbija) or Realm of Prince Lazar is the name used in historiography for the largest and most powerful Serbian principality to emerge from the ruins of the Serbian Empire (1371).[1] Moravian Serbia is named after Morava, the main river of the region.[2] Independent principality in the region of Morava was established in 1371, and attained its largest extent in 1379 through the military and political activities of its first ruler, prince Lazar Hrebeljanović.