Premysl Otakar I

Ottokar I (Czech: Přemysl I. Otakar; c. 1155 – 1230) was Duke of Bohemia periodically beginning in 1192, then acquired the title King of Bohemia, first in 1198 from Philip of Swabia, later in 1203 from Otto IV of Brunswick and in 1212 from Frederick. He was a member of the Přemyslid dynasty.

Ottokar's parents were Vladislaus II, Duke of Bohemia, and Judith of Thuringia. His early years were passed amid the anarchy that prevailed everywhere in the country. After several military struggles, he was recognized as ruler of Bohemia by Holy Roman Emperor Henry VI in 1192. He was, however, soon overthrown for joining a conspiracy of German princes to bring down the Hohenstaufen dynasty. In 1197, Ottokar forced his brother, Duke Vladislaus III Henry, to abandon Bohemia to him and to content himself with Moravia.

Taking advantage of the civil war in Germany between the Hohenstaufen claimant Philip of Swabia and the Welf candidate Otto IV, Ottokar declared himself King of Bohemia. This title was supported by Philip of Swabia, who needed Czech military support against Otto (1198).

In 1199, Ottokar divorced his wife Adelheid of Meissen, a member of the Wettin dynasty, in order to marry Constance of Hungary, the young daughter of Hungarian King Béla III.