Isidor (Issi) Frei was born in Steinach on August 15, 1892 as the first child of the merchant Bernhard Frei and his wife Rosa, née Löwenberger. The Frei family who came from Eichenhausen near Bad Neustadt had been living in Steinach at least since the middle of the 18^th century and had been butchers for generations. Isidor had six younger siblings who were also born in Steinach.

He attended Kissingen Realschule, the predecessor of contemporary Jack-Steinberger-Gymnasium, between 1902 and 1905 and lived with Meier Kahn in Hemmerichstrasse during that time. Obviously, Isidor’s father died before 1912. After that, his widow moved to Bad Kissingen, presumably together with her children.

Isidor Frei became a merchant and ran a wine business in Ludwigstrasse in the 1920s, which is still documented in the directory of 1934. His mother lived there, too. Isidor Frei was a member of the local Kissingen group of ‘Reichsbanner’, a paramilitary group founded in 1924 for the protection of the Republic, which numerous Jewish citizens of Bad Kissingen belonged to. 

In the first years of Nazi despotism, Issi Frei left the Franconian spa and moved to Munich. There he died on January 20, 1935 at the age of 42.