Otto, Duke of Austria

Otto the Merry (1301–1339), youngest son of Albert I, married Elizabeth of Bavaria, a Wittelsbach, in the reconciliation after the Habsburgs lost the German throne at Mühldorf in 1322. In 1327 he founded Neuberg Abbey in Styria on the birth of his first son, and from 1330 he ruled the Habsburg duchies with his brother Albert II.

In 1335 he married Anna of Bohemia, daughter of John the Blind. After their maternal uncle Henry of Carinthia died without male heirs, Emperor Louis IV enfeoffed the brothers with Carinthia and Carniola on 2 May 1335; Otto was enthroned as duke on the Zollfeld in the ancient Carantanian rite and thereafter governed Carinthia.

His nickname recalls the festive air of his court. He died at Neuberg in 1339, aged 37; his two sons died in 1344, presumably poisoned, and his line ended.