The War of the Galician Succession or War for the unification of the Principality of Galicia–Volhynia was a struggle for power over the Principality of Galicia–Volhynia. It took place from 19 June 1205 to 17 August 1245. The conflict was one of the longest wars of succession in Europe, and ended with the Romanovichi clan holding on to power.
The origins of the war can be traced to the death of Roman the Great at the Battle of Zawichost (1205). He left two sons, Daniel (Danylo) and Vasylko (the "Romanovichi", literally "Roman's sons"), who due to being underage were unable to ascend to the throne. The regency of their mother Anna-Euphrosyne, Roman's widow, was not widely accepted, resulting in a succession crisis. A number of contenders became involved in the struggle for power, including the Igorovichi, whom the local boyars invited to Halych (Galicia), hoping to stabilise the situation. The Igorovichi, 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 Romanovichi, led by regent Anna-Euphrosyne and supported by duke Leszek the White of Sandomierz, the Hungarians and some boyars, attempted to regain power in Halych. In 1211, Daniel was installed on the Halych throne, but the Romanovichi still had to contend with resistance from the Igorevichi and tensions among their own allies. This period was characterised by dynamic changes in alliances, short-lived victories and growing rivalry between the Romanovichi and the Hungarians, who sought full control of Halych.
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 the Romanovichi faction 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 in the late 1230s, which weakened both the Ruthenians and their neighbours, forcing the Romanovichi to temporarily move their capital to Kholm (present-day Chełm in Poland). The final years ended in a decisive victory for Daniel Romanovich. On his return from Kholm 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 Romanovichi in the Principality of Galicia–Volhynia.
Background
Over the course of the 11th and 12th centuries, the Kingdom of Poland (fragmented after 1138) had several conflicts with Kievan Rus' over the Cherven Cities, strategically located on the borders of both realms. Two separate Rus' appanages emerged in this area: the principalities of Halych (Galicia) and Volhynia. In 1183, thanks to the support of Casimir the Just, prince Roman the Great of Volhynia was established in Berestia (Brest), which started his political career. After Casimir's death, young Leszek the White ascended to the throne of Kraków (symbolising the heart of royal authority before Poland fragmented), prompting Mieszko III the Old to attempt seizing power over Kraków by taking advantage of Leszek's underage age, leading to the . In this clash, Roman of Volyn' supported Leszek of Sandomierz, which initiated an alliance between the two. Leszek returned the favour to Roman in 1199, supporting him in his fights for the throne of Halych and restoring him to power.
That same year, the latter united the principalities of Galicia and Volhynia to form a new state. Roman quickly consolidated his principality, making it one of the most powerful in Rus', in time even conquering Kyiv. However, in 1205, Roman unexpectedly broke the alliance and invaded Leszek's lands. The reasons for such a hasty decision remain unclear. Some chronicles point to Roman's support of duke Władysław III Spindleshanks of Greater Poland (based in Poznań) in his fight for the throne of Kraków; others to Leszek's possible claim for a tribute, as recorded in the Wielkopolska chronicle. Roman began the campaign with successes, capturing Lublin and Łuków, but at Zawichost his troops encountered the Poles in battle; Roman's forces were completely crushed and the prince himself died, ending his ambitions.
Phase I of the war 1205–1214: Igorevichi rule and Polish-Hungarian interventions
After the death of Roman the Great, his young sons, Daniel and Vasylko, called the Romanovichi after their father, inherited a state in political chaos. The return of Roman's political opponents and the claims of various dynasties to Galician and Volhynian regions complicated their situation. At the same time, Rurik Rostislavich, supported by the Olgovichi of Chernigov, invaded the lands of the young princes. In response, Roman's widow Anna Euphrosyne assumed the regency of Galicia–Volhynia, and requested help from King Andrew II of Hungary, who agreed to provide assistance. Despite the defeat of the Hungarian army at Mikulin, they managed to defend Halych against the allied forces of Rurik and the Olgovichi, temporarily repelling their claims. However, the situation deteriorated again in 1206, forcing the Romanovichi to flee.
After a series of political perturbations, the boyars elected Vladimir Igorevich to the Halych throne. The Hungarians and Poles attempted to stabilise their territories through intervention, which led to the division of Galician and Volhynian lands into spheres of influence. Hungarian intervention handed power in Halych to Benedict, whose rule quickly collapsed. The boyars of Halych resumed their allegiance with the Igorevichi, who, however, brutally dealt with them for an unknown reason by massacring them.
A surviving boyar, Vladislav Kormilchyc, called on the Hungarians and Poles for help. A joint expedition began, which initially ended with the defeat of the Hungarians at the River Luta. Eventually, however, Polish-Hungarian forces crushed the Igorevichi army at the Battle of Zvenigorod (1211), temporarily restoring stability in Halych. After Zvenigorod, Vladimir Igorevich's sons Roman, Rostislav and Sviatoslav were taken prisoner. In an act of retaliation for the earlier massacre, the boyars ransomed them and then hanged them. In 1212, the boyars expelled regent Euphrosyne from Halych, possibly due to her attempts to curb the power and influence of the boyars; nevertheless, a subsequent Hungarian intervention allowed her to return. In 1213, Euphrosyne once again lost power due to the actions of the boyars, who invited Peresopnytsian prince Mstislav the Nemesis to the throne.
The situation prompted the King of Hungary to launch another armed expedition, after which he installed Vladislav Kormilchyc as governor on the throne of Halych. In response, Euphrosyne turned to Leszek the White for help. The Polish princeps defeated Vladislav at the river Bóbrka, although he failed to capture Halych. But in retaliation he carried out a raid, plundering Galicia–Volhynia. As a result of this, the Poles and Hungarians concluded a treaty in Spiš, dividing Galicia–Volhynia into spheres of influence — the Poles were to take control of Volodymyr and the Hungarians of Halych.
Phase II of the war 1214–1227: Mstislav's appearance in Halych
The new arrangement for the division of influence in the Galicia-Volhynian principality quickly collapsed. In 1215, Daniel Romanovich (who had just reached adulthood and succeeded the regency of Euphrosyne) was supported by Leszek the White who, against the wishes of King Andrew II of Hungary, occupied Volyn's capital city of Volodymyr. This action was regarded by the Hungarians as a violation of the treaty, leading to antagonism. Meanwhile, prince Mstislav Mstislavich of Novgorod joined the conflict, and formed an anti-Hungarian coalition with the Romanovichi. Leszek, perceiving the threat, tried to extricate himself from the situation by making a deal with Hungary, which led to the outbreak of the so-called Polish-Hungarian-Ruthenian War (1218–1221).
The war began with Leszek's defeat in the Battle of Sukha Dorogva River (spring 1218). With the support of the Hungarians, Mstislav and Daniel were defeated at the Battle of Halych (1219). In 1220, Leszek conducted another expedition, which ended indecisively. In 1221, Mstislav launched a new offensive that ended in defeat. A few months later, the Novgorodian prince, reinforced by Rus' reinforcements, won a decisive victory at the second Battle of Halych (1221). The Hungarian crown prince Coloman was taken prisoner in battle. The peace negotiations ended favourably for Andrew II of Hungary; for Leszek the White, it was a complete defeat, resulting in the failure of his Rus' policy.
In 1223, a new threat appeared on the southern periphery of Kievan Rus' — the Mongol invasion, which culminated in the disastrous Battle of the Kalka River. This defeat, combined with the complete decimation of Rus' forces, significantly weakened the defensive capabilities of the Rus' princes there. The weakening of Kievan Rus' created new opportunities for political reshuffling in the ongoing struggle for the Halych succession. This time, Daniel Romanovich formed an alliance with Leszek the White, while Mstislav Mstislavich tied himself to Hungary. Mstislav, trying to take the initiative, suffered a series of defeats, starting with a battle in an unknown location, and ending with an unsuccessful expedition to Volhynia. The situation changed again, with Leszek reverting to co-operation with the Hungarians, while Daniel tied up with Mstislav. The new arrangement led to another campaign in which Lesser Poland (Sandomierz and Kraków) and Hungarian forces took part. However, it ended in a severe defeat at the Battle of Zvenigorod (1227), which further widened the anarchy in Halych.
Phase III of the war 1227–1241: Daniel's battles against the Hungarians