Rav Yehuda Meir Shapiro of Lublin’s father, Rav Yaakov Shimshon Katz of Shatz, Romania, was a descendant of Rav Pinchas Koretz, a talmid of the Ba’al Shem Tov. His mother, Margala, was the daughter of Rav Shmuel Yitzchok Shor, mechaber of Minchas Shai, and a descendant of the Tevu’as Shor. He was also a descendant of Rav Bechor Shor of Orleans, one of the Ba’alei Tosafos. He was married in 1906 and took his first appointment, Rav of Galina, in 1911. In 1921, he became Rav of Sanok, then in 1924 Rav of Piotrkov. It was while there that he wrote his sefer Or HaMeir. Also in 1923, he began the first cycle of Daf Yomi, having shared this idea at the first Knessia Gedola of Agudas Yisrael the previous year. That first cycle began on Rosh HaShana in 1923 and was completed 2702 days later on Tu Bishvat in 1931. His other major project was to found the Yeshiva Chachmei Lublin in 1930.
