R. Eliezer Hayyim b. Abraham Deutsch (1850–1916), was born in Petra, near Kaschau. He studied under R. Menahem Eisenstadt of Ungvar, R. Judah Aszod, and R. Solomon Ganzfried. In 1876 he was appointed rabbi of Hunfalu, and, in 1897, of the important community of Bonyhad, where he founded and headed a large yeshivah. R. Deutsch was a leader of Hungarian Orthodoxy, and a supporter of the "Moriah" association for the advancement of Orthodox Judaism, founded in 1905 by R. Meir Lerner in Altona. A prolific writer, his books are: Tevu'ot ha-Sadeh in six parts (1892–1904), novellae on talmudic themes with responsa appended to each part; Helkat ha-Sadeh (1901), glosses and notes on the Ara de-Rabbanan of R. Israel Jacob Algazi; Peri ha-Sadeh in four parts (1906–15), responsa; Si'ah ha-Sadeh (1914), aggadic novellae on the Torah and for festivals. Published posthumously were: Zemah ha-Sadeh (1917), novellae and responsa on the problems of agunot; Duda'ei ha-Sadeh (1929, published by his son, R. Moses), responsa and a selection of rulings with respect to the laws of mourning. In the Yizrah Or of R. David Meldola, there is an appendix by R. Deutsch, Omer ha-Sadeh, that comprises the laws for determining the New Moon. Halakhic queries were addressed to R. Deutsch from many parts of the world.