Beer Löb Isaak Kann lived in the 18th century. He was a member of the Kann family, the most powerful and richest Frankfurt Jewish family during the ghetto period. Under him the Kann family reached (and passed) the height of its power. Together with his brother Moses, who was not only a businessman but also the Klause rabbi and a highly respected Talmudist, Kann dealt with many princes. The Elector of Mainz and the Count of Hessen-Darmstadt (who was always in need of money because of his extravagant lifestyle) appointed him court factor. Within the Jewish community Kann had a dominant position. He held office as a treasurer managing the community finances. He succeeded in dominating the other treasurers and the "master builders" to the point where he was a virtual dictator in the Judengasse. Opposition to his rule emerged in 1749 under the leadership of the Kulp family. The bitter power struggles that resulted are known as the Kann-Kulp disputes. Isaak Kann's domination of the Jewish community was broken, and he not only lost much of his wealth but was also cast out from the community, the most severe sentence available to Jewish justice. He was also refused burial in the Jewish cemetery. Kann's sons had a measure of commercial success but the family never recovered the leadership it had long held among Frankfurt Jews.