The Sega Genesis, also known as Sega Mega Drive, is a fourth-generation video game console developed and produced by Sega. It was originally released in Japan in 1988 as Mega Drive (メガドライブ Mega Doraibu?), then in North America in 1989 as Sega Genesis, and in Europe, Australia and other PAL regions in 1990 as Mega Drive. The reason for the two names is that Sega was unable to secure legal rights to the Mega Drive name in North America. The Sega Genesis is Sega's third console and the successor to the Sega Master System with which it has backward compatibility when the separately sold Power Base Converter is installed.