The First Tevarin War was an intersystem conflict between the Tevarin and the United Planets of Earth (UPE). It began shortly after Tevarin-Human First Contact in SEY 2541, when the Tevarin declared war on Humans and launched a surprise attack. The motivations behind the war were complex; it was both a bid for the Tevarin to claim UPE-controlled territory to assuage their overpopulation problem and a consequence of the high cultural value the Tevarin as a people placed on combat. The war ended in 2546 with a UPE victory.

Ivar Messer, then an officer in the UPE Army, was propelled to power following the Battle of Idris IV, a key conflict in the First Tevarin War.