Rav Yehuda Mehler was born in 1661. He studied under Rav Yaakov Reischer, author of Shvus Yaakov, and Rav Gershon Ashkenazi, author of Avodas Hagershuni. His first rabbinical post was in Kleve and in 1708 he became the Rav of Deutz and the region around Cologne. He remained in that position until his passing in 1748. His son in law was Rav Yosef Yusfa Kashmann, author of Noheg Katzon Yosef, who was also his successor. His other son in law was Rav Shimon of Copenhagen who became famous for his position on the Gett of Kleve (listen to the podcast on kollelashkenaz.org/podcast). Rav Mehler received hundreds of halachic questions throughout his tenure and he meticulously recorded his replies. Some of these responsa have been published most of them remain in manuscript. He recorded many of his correspondents with leading Torah figures of the day.