Developed by Firaxis Games, Sid Meier's Civilization IV: Warlords is an all-new expansion pack that pays homage to some of history's greatest military leaders, delivering eight new scenarios, giving players the chance to change the course of history with the help of their new powerful "warlord" unit. The expansion pack is loaded with new civilizations, new leaders and more units, resources and wonders that can be used in both single and multiplayer games.