Ottocar II, king of Bohemia, born about 1230, killed in battle, Aug. 26, 1278. During his youth he headed an insurrection of the Bohemian nobles against his father, King Wen-ceslas L, which resulted finally in his defeat and imprisonment. After his release he gained possession of Austria and Styria by marrying Margaret, the widow of the duke of Austria, although she at that time was 46 years old, and he himself but 23. He succeeded his father in 1253, and in 1254 undertook a crusade against the pagan Prussians, which was completely successful. In July, 1260, he achieved a signal victory over the Hungarians. Having divorced his wife, he married the Hungarian princess Cunigunda in 1261, and in 1269 the duchies of Carinthia and Carniola came into his power. His dominions now extended from the borders of Bavaria to Raab in Hungary, and from the Adriatic to the Baltic. After the death of the German emperor Richard of Cornwall, he and Alfonso of Castile were candidates for the succession; but the choice fell on Rudolph, count of Hapsburg (1273). Ot-tocar refused to submit to his authority; but on Rudolph's marching into his dominions and laying siege to Vienna, he consented to a compromise by which he gave up his claims to Austria, Styria, Carinthia, Carniola, and the Windish territory (1276). Not long after he broke the treaty, but was defeated and slain in a battle on the Marchleld with the imperial troops.

Ottocar was a haughty and luxurious prince, but greatly increased the prosperity of his subjects by promoting equality and justice and founding cities and schools. - See Lorenz, Die Geschichte Ottolcars ton Bohmen (Vienna, 1866).