entrusted to Rudolph's representatives, leaving Ottokar's widow Kunigunda of Slavonia, in control of only the province surrounding Prague, while the young Wenceslaus II was again betrothed to Judith. Rudolf was thus able to assume sole control over Austria, as Duke of Austria and Styria (1278–1282) which remained under Habsburg rule for over six centuries, until 1918. The establishment of the Habsburg dynasty: Duchy of Austria (1278–1453) Thus Austria and the Empire came under a single Habsburg crown, and after a few centuries (1438) would remain so almost continuously (see below) till 1806, when the empire was dissolved, obviating the frequent conflicts that had occurred previously. Rudolph I and primogeniture (1278–1358) Rudolf I spent several years establishing his authority in Austria, finding some difficulty in establishing his family as successors to the rule of the province. At length the hostility of the princes was overcome and he was able to bequeath Austria to his two sons. In December 1282, at the Diet of Augsburg, Rudolph invested the duchies of Austria and Styria on his sons, Albert I (1282–1308) and Rudolph II the Debonair (1282–1283) as co-rulers "jointly and severally", and so laid the foundation of the House of Habsburg. Rudolf continued his campaigns subduing and subjugating and adding to his domains, dying in 1291, but leaving dynastic instability in Austria, where frequently the Duchy of Austria was shared between family members. However Rudolf was unsuccessful in ensuring the succession to the imperial throne for the Dukes of Austria and Styria. The conjoint dukedom lasted only a year until the Treaty of Rheinfelden (Rheinfelder Hausordnung) in 1283 established the Habsburg order of succession. Establishing primogeniture, then eleven-year-old Duke Rudolph II had to waive all his rights to the thrones of Austria and Styria to the benefit of his elder brother Albert I. While Rudolph was supposed to be compensated, this did not happen, dying in 1290, and his son John subsequently murdered his uncle Albert I in 1308. For a brief period, Albert I also shared the duchies with Rudolph III the Good (1298–1307), and finally achieved the imperial throne in 1298. On Albert I's death, the duchy but not the empire passed to his son, Frederick the Fair (1308–1330), at least not until 1314 when he became co-ruler of the empire with Louis IV. Frederick also had to share the duchy with his brother Leopold I the Glorious (1308–1326). Yet another