War of Bohemian Succession (1125–1140)

The War of Bohemian Succession (1125–1140) was a dynastic conflict fought for control of the Duchy of Bohemia following the death of Duke Vladislaus I in 1125. Vladislaus had designated his cousin Otto II the Black, Duke of Olomouc, as his successor, bypassing his younger brother Soběslav I. This succession plan was controversial and immediately challenged upon Vladislaus's death.

Soběslav, despite his brother's wishes, claimed the ducal throne, asserting his right through traditional seniority. He quickly rallied support among a significant portion of the Bohemian nobility who were dissatisfied with Otto's perceived weakness and his strong ties to the Holy Roman Empire.

The conflict ignited with Soběslav leading a military campaign against Otto. The key battle of the war took place at Chlumec in 1126, where Soběslav's forces decisively defeated Otto's army. Otto II was killed in the battle, effectively eliminating him as a contender for the throne.

Although the victory at Chlumec solidified Soběslav's position, the war did not immediately end. Various factions within Bohemia continued to resist his rule, fueled by resentment over the violent overthrow of the established succession plan. Soběslav spent the subsequent years consolidating his power through military campaigns and political maneuvering, suppressing rebellions and securing alliances.

The war officially concluded around 1140 with Soběslav's death. Although his reign was marked by conflict, he successfully established his dynasty. His son, Vladislaus II, eventually succeeded him as Duke of Bohemia, despite initial challenges from rival claimants. The War of Bohemian Succession had significant implications for the political landscape of Bohemia, impacting the relationship between the Duke, the nobility, and the Holy Roman Empire, and ultimately shaping the future of the Přemyslid dynasty.