During the mid 13th Century relations between the Barons of Regensberg and the city of Zürich became strained. At about this same time, the barons began to argue with the Habsburgs over who would inherit the lands of the now extinct Kyburg family. In 1267 the disputes led to war between the barons and the combined Zürich and Habsburg forces. The barons lost this war, and rapidly declined in power over the following half century. In 1302 they sold Regensberg to the Habsburgs.