Concentrating on the late medieval period, Age of Chivalry: Hegemony replaces or significantly alters each of the civilizations in the original game, while adding a number of new ones, allowing the player to control Central and Western European states. Many new units and technologies have been added and gameplay dynamics have been changed considerably in this complete overhaul of Age of Empires II.
Some screenshots from Age of Chivalry: Hegemony, showing a variety of new architecture and units (also incorporating some material, with permission, from Wildifre Games' Rome at War mod for the same game) as well as the in-game menu.