Rabbi Yehoshua Yehudah Leib Diskin, (1818–1898), also known as the Maharil Diskin, was an important Talmudist and Biblical Commentator. He served as a rabbi in Łomża, Mezritch, Kovno, Shklov, Brisk and finally Jerusalem after moving there in 1878, where he became the spiritual leader of a part of the Yishuv haYashan.
Rabbi Yehoshua Yehudah Leib was born in Grodno, then part of the Russian empire, in 1817. His father, Rabbi Binyamin Diskin, was Rabbi of that city, then Volkovisk and later Łomża. He was engaged before his Bar Mitzva and at the age of fourteen he married the daughter of Rabbi Brode and lived with his father-in-law in Wolkowitz. He received semicha at the age of 18 and inherited his father's rabbinate of Łomża at the age of 25.
Along with such luminaries as Rabbi Yitzchak Elchanan Spektor of Kovno (with whom Rabbi Diskin maintained a lifelong friendship), Rabbi Jacob Joseph of Vilna, Rabbi Azriel Hildesheimer of Berlin, Rabbi Eliyahu Levinson of Krotingen, and Rabbi Chaim Berlin of Moscow, Rabbi Yehoshua Leib was offered the position of Chief Rabbi of New York in the 1880s, but wasn't interested in it.
Rabbi Diskin's second wife, Sarah, was famed as the "Brisker Rebetzen". She had a very strong mind and came from a prestigious family—she was descended from Rabbi Yechezkel Landau (the Nodah bi-Yehudah) and was also descended from the wealthy family of Joshua Zeitlin. She brought 40,000 rubles into their marriage - a huge sum in those days - with which the couple established the "Diskin Orphanage" in Jerusalem in 1880. She died in 1907.
Exceptional scholars such as Rabbi Chaim Soloveitchik and Rabbi Meir Simcha of Dvinsk were in awe of Rabbi Diskin, as was his famously brilliant pupil Rabbi Yosef Rosen, the Rogatchover Gaon. Rabbi Diskin established a yeshiva by the name of Ohel Moshe, (Tent of Moses). He held the line against attempts by maskilim to introduce secular institutions to Jerusalem. He died in 1898, on 29 Teiveith 5658. His son is Rabbi Yitzchok Yeruchem Diskin.
The Braverman variety of original Palestinian etrog is claimed to be witnessed by Rabbi Diskin.