The Nobunaga's Ambition franchise is a series of turn-based strategy games developed by Koei set in Japan's Warring States era. The series takes its name from the historical figure Nobunaga Oda, whose ambition to control all of Japan exceeded all of the warlords that had come before him, and yet remained just out of his reach. The series was created by Yoichi Erikawa, who had originally co-founded Koei as a chemical wholesaling company; he developed the original game in his spare time. The game's success upon its release in 1983 led to his conversion of the company into a video game developer. The NES version of the original game was released in North America in 1988.
Since its inception, the Nobunaga's Ambition series has seen releases on most major platforms ranging from the PC and NES to the PS3 and Xbox 360, with variants and ports appearing on handhelds ranging from the Game Boy to the DS. The franchise has also expanded into the realm of social games and an MMO, and in 2012 saw a special crossover title with the Pokemon series.