Japan's largest political party, which held power almost continuously from its formation in 1955 until 1993. It was created through the amalgamation and transformation of various factions of the prewar Rikken Seiykai and Minseit parties. The conservative LDP appeared threatened in the 1970s but survived; the end of the 1980s boom years (the "bubble economy"), financial crises, and political scandals finally caused the party to lose its majority in the Diet in 1993. It came back to power in a coalition government in 1994, and since then LDP prime ministers have included Obuchi Keiz and Koizumi Jun'ichir