 Upon Duke Bretislav's assassination in 1100, Emperor Henry IV confirmed the accession of Bořivoj to the Prague throne; nevertheless Luitpold and Ulrich enforced their return to Moravia and the restoration of the Brno duchy - with the help of Austrian and Bavarian armed forces as well as with indirect support by the emperor, whom the brothers visited in early February 1101 in Frankfurt.After they returned, they continued to reign in the two principalities of Brno and Znojmo in certain territorial union.Emperor Henry IV gave Ulrich insignia of rank and banner ("vexillum") for their reign as Moravian dukes, while Luitpold's brother officially renounced all claims to the Prague throne.