Yehuda Loevy, or Judah Loew ben Bezalel, (COMIC: The Broken Man) was the rabbi of the Altneuschul in the 16th century. When a piece of clay from a Liciax ship fell to Earth, Rabbi Loevy used it to create the Golem of Prague. When it proved too dangerous, the First Doctor had him lock it in an upstairs room of the Altneuschul. (PROSE: Life from Lifelessness)
Rabbi Loew also created the book The Sorrows of Prague as a prison for the Mavora Collective, using psychic metal which had fallen from the sky. According to one account, this psychic metal transformed Gerhard Frankel into the Golem of Prague, rather than Loew creating the Golem outright. (COMIC: The Broken Man)