Even though Regensburg in Bavaria is often quoted in literature as Isserlein's birthplace it is now clear that he was born in the Styrian Maribor or Marburg an Drau, present-day Slovenia, in the last decade of the 14th century.
After an early death of his father, it appears, he and his mother moved to Krems, where his uncle R. Aron Bluemlein of Krems/Vienna was teaching, and was together with his mother a victim of Viennese Gzerah in 1421.