God of War is a mythology-based action-adventure game franchise created by David Jaffe at Sony's Santa Monica Studio. It began in 2005 on the PlayStation 2 (PS2) video game console, and has become a flagship title for the PlayStation brand, consisting of eight games across multiple platforms. The story is about Kratos, a Spartan warrior who was tricked into killing his wife and daughter by his former master, the Greek God of War Ares. What follows are a series of events that puts him into constant conflict with the gods, leading to wars with the mythological pantheons. The Greek mythology era of the series sees Kratos follow a path of vengeance due to the machinations of the Olympian gods, while the Norse mythology era, which introduces his son Atreus as a secondary protagonist, shows Kratos on a path of redemption, which inadvertently brings the two into conflict with the Norse gods.