Bernold of St Blasien writes that Duke Welf of Bavaria prevented a conference that Emperor Henry IV "had arranged with the king of the Hungarians" in December 1092. A letter written by Henry refers to "the alliance into which once entered" with Ladislaus. Pope Urban II also mentioned that the Hungarians "left the shepherds of their salvation", implying that Ladislaus had changed sides and acknowledged the legitimacy of Antipope Clement III. In the deed of the Benedictine Somogyvár Abbey, Ladislaus stated that the abbot should be obedient to him, proving that Ladislaus opposed the Church's independence, which was demanded by the Gregorian Reforms. Ladislaus personally presided over an assembly of the Hungarian prelates that met in Szabolcs on 21 May 1091. The synod recognized the legitimacy of a clergyman's first marriage, in contrast to the requirements of canon law, which states that members of the clergy may not marry at all. According to a scholarly theory, the sees of the dioceses of Kalocsa and Bihar were moved to Bács (now Bač, Serbia) and Nagyvárad (present-day Oradea, Romania), respectively, during Ladislaus's reign.