The first Call of Duty game was released, marking the beginning of the popular military shooter video game franchise.
Release of Call of Duty 4: Modern Warfare, a significant shift in the series to modern warfare settings, greatly influencing the FPS genre.
Launch of Call of Duty: Black Ops, introducing Cold War themes and becoming one of the best-selling games in the series.
Release of Call of Duty: Warzone, a free-to-play battle royale game that significantly expanded the player base.