In the process of researching so many families and generations, Jacobi devised a unique dating system, which he called “Absolute Generations”, in order to situate individuals on their family trees, synchronize them with their peers and, finally, locate them within wider kinship groups The lecture will describe Jacobi’s work, his contribution to Jewish genealogy and Ashkenazic history, as well as the challenges in publishing this important study. 

Dr. Paul J. Jacobi (Königsberg/Jerusalem,1911-1997) investigated and documented the lineages of leading Ashkenazi families, many of whom were of rabbinic descent.
Jacobi held the challenging view that a core-group of some 80 elite families dominated Ashkenazi Jewry from its beginnings. To evaluate his theory, he researched more than 450 families to varying levels of detail. Of these, he brought more than 100 of his studies to completion. On his death, his manuscripts were deposited in the National Library of Israel.

Recently, Emanuel Elyasaf edited Jacobi’s papers which have been published in four hard copy volumes by the International Institute for Jewish Genealogy (IIJG).