Originally Cahn, Cahen, Cohen or Katz was not the name of an individual family but the Hebrew term for the tribe of priests, and thus of every Biblical Jewish family which belonged to the priesthood. The name Katz derives from a contraction of the Hebrew title Cohen Zedek ("the righteous priest"). While the Cahn family name always indicates descent from the original priestly tribe, the majority of priestly families have over the years adopted other family names. There were several Cahn families in Frankfurt who were not interrelated. The oldest and most influential Cahn family is known by the name of its family home, the Haus an der Pforte, in which they lived from 1515 onwards. The family's descendants lived for three hundred years in the corner house at the Gate and also in the separate but adjoining houses Wedel, Grüne Tür. Goldene Zange, and Rote Tür. Their association with these houses was more enduring than that of any other family in the Judengasse. Whilst the Cahns were amongst the wealthiest members of the community in 1555, subsequent generations were mostly poor. In the 19th century several members of the family made their living as secondhand clothes dealers. Another Cahn family was founded by chief rabbi Jakob Hakonen Popers , who was summoned to take up the Frankfurt post in 1717.