Moravian Serbia (Serbian: Моравска Србија / Moravska Srbija) is the name used in historiography for the largest and most powerful Serbian principality to emerge from the ruins of the Serbian Empire (1371). Moravian Serbia is named after Morava, the main river of the region. 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. In 1402 it was raised to the Serbian Despotate, which would exist until 1459 (de jure until the 1560s).
The adjective Moravian does not imply that the state (Moravian Serbia) is affiliated in any way with the region of Moravia in the present-day Czech Republic. The term Moravian Serbia refers to the fact that the state comprised the basins of the Great Morava, West Morava, and South Morava rivers in present-day central Serbia.