War of the Galician Succession (1205–1245)

The War of the Galician Succession or War for the unification of the Principality of Galician-Volhynia (Ukrainian: Війна за об'єднання Галицько-Волинського князівства) ; Russian: Война за объединение Галицко-Волынского княжества) sometimes also known as the Second War of the Galician Succession was a struggle for power over the Principality of Galicia-Volhynia. It took place from 19 June 1205 to 17 August 1245. The war is one of the longest wars of succession in Europe and ended with the Romanovichi dynasty coming to power.

First years of war began after the death of Roman the Great at the Battle of Zawichost. He left two minor sons, Daniel and Vasylko, who were unable to take power because of age, resulting in a succession crisis. A number of contenders became involved in the struggle for power, including the Igorovichs and the Halych boyars, who invited them to Halych, hoping to stabilise the situation. The Igorovichs, supported by the Hungarians, initially gained the upper hand, but their brutal rule, including the massacre of boyars, provoked resistance and weakened their position. The Romanovichs, supported by Leszek the White, the Hungarians and some boyars, attempted to regain power in Halych. In 1211, Daniel was installed on the Halych throne, but still had to contend with resistance from the Igorevichs and tensions among his own allies. This period was characterised by dynamic changes in alliances, short-lived victories and growing rivalry between the Romanovichs and the Hungarians, who sought full control of Halich. Although Daniel managed to consolidate his position, the situation in the region remained unstable.

The following years were dominated by the rivalry between the Hungarians and the Romanovichs. In 1214, Leszek the White made an agreement with King Andrew II of Hungary in an attempt to divide spheres of influence in the Principality of Halych. This agreement led to a short-lived strengthening of Hungarian influence, but resistance from Daniel and his allies made it impossible to maintain permanent control over the region. Key clashes, such as the Battle of Halych in 1229, highlighted the fierceness of the fighting, but failed to produce a clear-cut settlement. The situation was further complicated by Mongol incursions, which weakened both the Ruthenians and their neighbours, forcing the Romanovichs to temporarily withdraw to Polish lands. Recent years ended in a decisive victory for Daniel Romanovich. On his return from Poland in 1241, Daniel began to rebuild his position, reclaiming Halych and waging further campaigns against his opponents. The war culminated in the Battle of Yaroslavl in 1245, in which Daniel, supported by the Polovtsians, defeated the forces of Rostislav, Béla IV and Boleslav the Chaste. This victory ended the 40-year struggle for the succession and consolidated the power of the Romanovichs in the Principality of Galicia-Volhynia.