Age of Empires is a series of computer video games developed by Ensemble Studios and published by Microsoft Game Studios. The first title of the series was Age of Empires, released in 1997. Since then, seven titles and three spin-offs have been released. The titles are historical real-time strategy games, and their gameplay revolves around two main game modes: random map and campaign.

The games are set amidst historical events. The first two games focused on events in Europe and Asia Minor, spanning from the Stone Age to the Classical period; one game explored the formation and expansion of the Roman Empire. The next two games were also set in the Middle Ages and the Spanish conquest of Mexico. The subsequent three games explored the early modern period, when Europe was colonizing the Americas and several Asian nations were on the rise. A spin-off game, Age of Mythology, was set in the same period as the original Age of Empires, but focused on fictional elements of Greek, Egyptian, and Norse mythology.

The Age of Empires series has been a commercial success, selling over 20 million copies. The popularity and quality of the games has earned Ensemble Studios a strong reputation in real-time strategy gaming. Ensemble collaborated with Big Huge Games on Age of Empires III: The Asian Dynasties. Critics have credited part of the success of the series to its historical theme and fair play; the artificial intelligence (AI) players fight with less "cheating" than in many of the series' competitors.

Common gameplay elements

The missions in a campaign generally follow a historical setting and focus, yet do not strive for absolute historical accuracy. For example, while Germany in the early modern period  when Age of Empires III was set  was largely Protestant, the design of the German church building is Catholic. However, in The WarChiefs, the design team did take great care to ensure they portrayed Native Americans as accurately as possible, and relied on expert historians for assistance. Age of Empires games use historical figures and units that are relatively well-known, but also include several "strange or exotic military unit1," to make the games more interesting. The series' sporadic faithfulness to history has earned it criticism; critics have generally panned the notion of unhistorical skirmishes such as "Japanese vs. Vikings and Franks vs. Persians," none of whom ever fought.