The first mention of land belonging to Jews dates from 1255. Friesach with its toll was in the 14th century an economically thriving town and boasted the most important Jewish community in Carinthia at that time.
The Jews, who were subjects of the Archbishop of Salzburg, had a synagogue (later at Stiftsgasse 9) and a cemetery (in Judendorf), which had existed since 1293. In 1343 a young Jewish woman converted to Christianity. The customers of the Jewish moneylenders were mostly secular and clergy noblemen. Rabbi Suezzlein, a juden maister (representative of the Jewish community) lived in Friesach around 1351. In 1368 a Jew converted to Christianity.