Yisrael Hopstein (1737–1814), also known as the Maggid of Kozhnitz, was one of the more important Hasidic leaders of Poland during the 18th and early 19th century . He was a student of the Magid of Mezritch and the Rebbe Reb Melech Elimelech of Lizhensk. He wrote many books on Hasidut and Kabalah.
He was born in Opatów, to his father, Shabtay, who was a bookbinder, and his mother, Perl. Even as a young child he was recognized as an Illui, a prodigy. He studied under the tutelage of Rabbi Shmelke of Nikolsburg, who eventually convinced R' Israel to go learn with the Magid of Mezritch. After the passing of the Maggid, he went to learn from the Rebbe Reb Melekh Elimelech of Lizhensk. He was founder of the Kozhnitz Hasidic dynasty.
He was married to Royze. They had 3 children, (two sons and one daughter): Rabbi Moshe Elyakim who eventually replaced his father as Rebbe after R' Yisroel's passing, Leah Perl (who married R' Avi Ezra Zelig Shapira, Rabbi of Grenitz), and, R' Mottel, who passed away in his youth.