Isserles

Isserles is a Jewish surname of Ashkenazi origin. The most prominent bearer is Moses Isserles (c. 1530–1572), a leading Polish rabbi and halakhic authority based in Kraków. He is commonly known by the acronym Rema, from Rabbi Moses Isserles.

Isserles is best known for his work on the Shulchan Aruch, the code of Jewish law compiled by Joseph Karo. He authored the Mapah (also spelled Mappa), a comprehensive gloss that presents Ashkenazi customs and practice. The Mapah is appended to the Shulchan Aruch and serves to harmonize the Sephardic code with Ashkenazi minhagim, thereby shaping the standardized practical halakha used by Ashkenazi communities for centuries. This collaboration between Karo’s Sephardic framework and Isserles’s Ashkenazi perspective helped unify Jewish legal practice across major communities.

The surname Isserles itself appears as a variant form of Isserlis/Isserlēs, reflecting Ashkenazi naming patterns in Central and Eastern Europe. It indicates lineage or origin associated with Jewish families in that region, with dispersion to the wider Jewish diaspora in the modern era.

In scholarship and religious life, Moses Isserles’s influence endures through the Mapah, the prominence of Kraków in Ashkenazi tradition, and the ongoing use of the Shulchan Aruch with Ashkenazi glosses in many Orthodox communities. See also: Rema.