From Sega Retro
Koei Co., Ltd. (株式会社コーエー Kabushiki gaisha Kōē, formerly 光栄 (Kōei)) is a Japanese video game publisher, developer, and distributor founded in 1978. The company is best known for its historical simulation games based on the novel Romance of the Three Kingdoms, as well as simulation games based on historical events.
The company has also found mainstream success in a series of loosely historical action games, the flagship titles of which are Dynasty Warriors (真・三國無双 (Shin-Sangoku Musō)) and Samurai Warriors (戦国無双 (Sengoku Musō)), the Musō (無双) series. Koei also owns a division known as Ruby Party, which focuses in dating sim games.
Koei was established in July 1978 by Yoichi Erikawa and Keiko Erikawa. Yoichi was a student at Keio University, and when his family's rural dyestuffs business failed he decided to pursue his interest in programming. The company to this day is located in the Hiyoshi area of Yokohama along with Erikawa's alma mater, and the company's name is simply a spoonerism of the school's.
The company initially focused on personal computer sales and made-to-order business software. In 1983 it released Nobunaga's Ambition (信長の野望 Nobunaga no Yabō), a historical strategy game set during the Sengoku period of Japanese history. The game went on to receive numerous awards, and Koei produced several more such games set against the backdrop of world history, including Romance of the Three Kingdoms, set during the Three Kingdoms period of Chinese history, and Uncharted Waters (大航海時代 Dai Kōkai Jidai; lit. Great Navigation Era), set in Portugal during the Age of Exploration.
In 1988, Koei established a North American subsidiary, Koei Corporation, in California. This subsidiary localized Koei games for export to all territories outside of Japan, as well as producing original games and concepts with the leadership of designer Stieg Hedlund. After Hedlund's departure, this subsidiary ceased game development in 1995, focusing instead on localization, sales and marketing.
On September 4, 2008, Koei announced that it was in talks to purchase ailing competitor Tecmo. They agreed in November 2008 to merge on April 1, 2009 to form Koei Tecmo, with the combined American division being named Tecmo Koei. On January 26, 2009 the two companies approved the merger, and the holding company formed on April 1, 2009, as planned.
note: the remainder of list is/might be wrong/incomplete due to region-specific releases