Kingdom of Galicia–Volhynia

The Principality of Galicia–Volhynia, or Kingdom of Ruthenia (Old Ruthenian Галицко-Волинскоє князство, Королѣвство Русь, Ukrainian: Галицько-Волинське князівство, Королівство Русі, Latin: Regnum Galiciae et Lodomeriae, Regnum Russiae), was a state in the regions of Galicia and Volhynia of present-day Ukraine that was formed after the conquest of Galicia by the Prince of Volhynia Roman the Great with the help of Leszek the White of Poland. Roman the Great united the principalities of Halych (Galicia) and Volhynia into a state that existed from 1199 to 1349. Along with Novgorod and Vladimir-Suzdal, it was one of the three most important powers to emerge from the collapse of Kievan Rus'.

After the enormous destruction wreaked by the Mongol invasion of Kievan Rus' in 1239–41, Prince Danylo Romanovych was forced to pledge allegiance to Batu Khan of the Golden Horde in 1246. He strove to rid his realm of the Mongol yoke, however, by a formal orientation to western Europe (coronation as a "Rex Rusiae" by a papal legate in 1253) and by attempting, unsuccessfully, to establish military alliances with other European rulers. The Polish conquest of the kingdom in 1349 ended its vassalage to the Golden Horde.