The Tau Empire is a fictional faction in the Warhammer 40,000 universe, known for its advanced technology and emphasis on cooperation. Founded by the Tau, a humanoid alien race, the Empire promotes the philosophy of the "Greater Good," which encourages unity among different species. The Tau utilize powerful weapons and vehicles, including the iconic Crisis Battlesuits. The Tau Empire is organized into several castes, each responsible for different aspects of society, such as the Fire Caste for military operations and the Earth Caste for engineering and construction. Their expansionist policies often lead to conflicts with other factions, including the Imperium of Man and Orks.