Hatoyama, who was born in Bunkyō, Tokyo, is a fourth-generation politician. His paternal great-grandfather, Kazuo Hatoyama, was speaker of the House of Representatives of the Diet of Japan from 1896 to 1897 during the Meiji era. Kazuo later served as the president of Waseda University. His paternal great-grandmother, Haruko Hatoyama, was a co-founder of what is known today as Kyoritsu Women's University. His paternal grandfather, Ichirō Hatoyama, was a major politician; he served as Prime Minister and was a founder and the first President of the Liberal Democratic Party in 1956. As Prime Minister, he restored diplomatic relations with the Soviet Union, which cleared the way for Japan's membership in the United Nations.