Bio (https://en.wikipedia.org/wiki/Yaakov_ben_Moshe_Levi_Moelin):
Yaakov ben Moshe Levi Moelin (Hebrew: יעקב בן משה מולין) (c. 1365 – September 14, 1427) was a Talmudist and posek (authority on Jewish law) best known for his codification of the customs (minhagim) of the German Jews. He is also known as Maharil (Hebrew: מהריל) – the Hebrew acronym for “Our Teacher, the Rabbi, Yaakov Levi” – as well as Mahari Segal or Mahari Moelin. Maharil’s Minhagim was a source of law for Moses Isserles’ component of the Shulkhan Arukh.
