During his reign he stood in the shadow of his brother Eberhard II. Because of that he temporarily strove towards the division of the realm. This is the reason why Eberhard II forced him to sign a treaty that stipulated the indivisibility of the county on 3 December 1361. Soon after that Ulrich relinquished his participation in the government of Württemberg on 1 May 1362.
This article is translated from that on the German Wikipedia