This is the name given to the violent conflict between the Kulp and Kann families in the 1750s for domination within the Jewish community. The Kann family had been one of the richest families in the Judengasse for about two centuries, and through its tenure of the leading offices had acquired a dominant influence within the community administration. In the process, family interests had become bound up with the official rights and duties of these positions, which was not uncommon in those days. This was particularly true of Bär Löb Isaak Kann, who was one of the community treasurers in the mid18th century. As the head of the Kann family he felt he had a right to exercise a very personal management style, bypassing the other members of the community administration. He is described as having ruled the Judengasse "with the arrogance of a prince".
Opposition to this personal rule appeared in 1749 under the leadership of another rich and powerful man, David Mayer Kulp, and efforts were made to force Kann to public disclosure of his administration of community funds. Another aim of the opposition was to elect new community leaders who, unlike the previous ones, did not owe personal loyalty to Kann. The disputes between Kann and Kulp involved most of the inhabitants of the Judengasse and split them into two hostile camps. The conflict shook community life for years. The city council and emperor repeatedly tried to intervene in the struggle, and for years the city militia were needed to keep the peace in the Judengasse. It took years before new "master builders" could be elected and a new system created to deal with the internal affairs of the Judengasse. Although the new system of community administration retained many of the features of the old, the dominance of the Kann family was finally broken. Both David Kulp and Isaak Kann suffered heavy financial and moral losses through the years of conflict.