Jan Abraham Ezofowicz

Jan Abraham Ezofowicz was a Jewish financier living in Poland. In partnership with his brothers, Michal and Ayzyk, he was initially a merchant and leaseholder for tolls in the Kiev region of Poland–Lithuania. After the destruction of Kiev by Tatars in 1482 he moved to Lithuania. In 1488, Jan converted to Orthodox Christianity, and became an official for the grand Duke of Lithuania Casimir IV Jagiellon (r. 1440 – 1492), again administering towns and tolls.

In 1504, for his service to the king Alexander I Jagiellon (r. 1501 – 1506) and support during the wars with Muscovy, Jan was rewarded with a land grant in the region of Wilno and was ennobled in 1507. Jan continued to serve Alexander’s successor, Sigismund I of Poland (r. 1506 – 1548), under whom, in 1509, was appointed head of the royal treasury and was responsible for reforming the institution.