Rabbi Meir Simcha HaKohen, the "Ohr Sameyach", was chief rabbi of the Mitdnagim in Dvinsk from 1887-1926. His "Meschech Chochmah", an oft-quoted commentary on the Torah, was written in his early years but published posthumously. A later work, "Ohr Sameyach," (the happy light) is a commentary on Rambam's (Maimonides) writings. Most of his responsa (rulings on Jewish law) and other writings were destroyed in the Holocaust.

Links to brief and longer biography of Rabbi Meir Simcha of Dvinsk, and a listing for a book length biography, can be found on the Daugavgpils Jewish History page.