Otto IV, the Merry (German: der Fröhliche; 23 July 1301 – 17 February 1339), a member of the House of Habsburg, was Duke of Austria and Styria from 1330, as well as Duke of Carinthia from 1335 until his death. He ruled jointly with his elder brother Duke Albert II.
Otto was born in the Austrian capital Vienna, the youngest son of King Albert I of Germany and Elizabeth of Carinthia, a member of the House of Gorizia-Tyrol (Meinhardiner). His elder brothers were Rudolf III, who beame King of Bohemia in 1306, Frederick the Fair, elected King of the Romans in opposition to Louis the Bavarian in 1314, the Austrian dukes Leopold I and Albert II as well as Henry the Friendly.
After the murder of King Albert I in 1308, the Habsburgs lost out in the struggle around the German throne, when Frederick the Fair was defeated by his Wittelsbach rival Louis in the 1322 Battle of Mühldorf. In the course of a rapprochement of both dynasties, Otto married Elizabeth of Wittelsbach, a daughter of Duke Stephen I of Bavaria. In 1327 he founded Neuberg Abbey in Styria, on the occasion of the birth of his first son Frederick II, and the Chapel of Saint George in the Augustinian Church in Vienna. When his wife Elizabeth died in 1330, she was buried at the Neuberg Abbey church.
From 1329 onwards, Otto administrated the original Habsburg possessions in Swabia (Further Austria). In 1330, he and his brother Albert II were enfeoffed with the Austrian duchy. Louis IV, Holy Roman Emperor since 1328, also vested Otto with the title of an Imperial vicar. In February he developed close ties with the mighty House of Luxembourg by secondly marrying Anna of Bohemia, daughter of King John the blind and sister of future emperor Charles IV, in the Moravian royal city of Znojmo.
Two months later, Otto's maternal uncle, the Meinhardiner duke Henry of Carinthia died without male heirs, whereupon Emperor Louis IV on May 2, 1335 ceded the Duchy of Carinthia, the adjacent March of Carniola and the southern part of the Tyrol to Otto and Albrecht as Imperial fiefs in Linz. Otto was enthroned as duke in accordance with the archaic Carantanian rite on the Zollfeld plain, and, from that time onwards, took care of Carinthia rather than of the Austrian duchy. In 1337 he founded the knightly order Societas Templois for the crusade against the pagan Prussian and Lithuanian tribes. His nickname the Merry refers to the festive life at his court.
Otto died at Neuberg Abbey at the age of 37. His sons and titular successors Frederick II and Leopold II died shortly afterwards in 1344 (presumably poisoned), and the line became extinct.
Marriages and children
Duke Otto and his two sons, Neuberg Abbey
On 15 May 1325, Otto married his first wife Elizabeth of Bavaria. She was a daughter of Stephen I, Duke of Bavaria and Jutta of Schweidnitz. They had two children:
Frederick II (10 February 1327 – 11 December 1344)
Leopold II, Duke of Austria (1328 – 10 August 1344)
Elizabeth of Bavaria died on 25 March 1330. Otto remained a widower for almost five years. On 16 February 1335, Otto married his second wife Anna of Luxembourg, daughter of King John of Bohemia and his first wife Elizabeth, a member of the Přemyslid dynasty. They would have no children. Anna died on 3 September 1338.
Otto had four illegitimate sons who appear in genealogies. The identities of their mother or mothers and their later fates are unknown:
Ancestors of Otto, Duke of Austria
16. Rudolph II, Count of Habsburg
8. Albert IV, Count of Habsburg
17. Agnes of Staufen
4. Rudolph I of Germany
18. Ulrich, Count of Kiburg and Dillingen
9. Heilwig of Kiburg
19. Anna von Zähringen
2. Albert I of Germany
20. Burckhard IV, Count of Hohenburg
10. Burckhard V, Count of Hohenburg
5. Gertrude of Hohenburg
22. Rudolph II, Count Palatine of Tübingen
11. Mechtild of Tübingen
1. Otto, Duke of Austria
24. Engelbert III, Count of Gorizia
12. Meinhard I of Gorizia-Tyrol
25. Matilda of Andechs
6. Meinhard, Duke of Carinthia
26. Albert IV, Count of Tyrol
13. Adelaide of Tyrol
27. Uta of Frontenhausen
3. Elisabeth of Tirol
28. Louis I, Duke of Bavaria
14. Otto II Wittelsbach, Duke of Bavaria
29. Ludmilla of Bohemia
7. Elisabeth of Bavaria
30. Henry V, Count Palatine of the Rhine
15. Agnes of the Palatinate
31. Agnes of Hohenstaufen
Otto, Duke of Austria
House of Habsburg
Born: 23 July 1301Died: 17 February 1339
Preceded by Frederick I
Duke of Austria and Styria Count of Habsburg jointly with Albert II/VI 1330–1339
Succeeded by Albert II/VI (alone)
Preceded by Henry VI
Duke of Carinthia jointly with Albert II 1335–1339