quadrumvirate
noun
- government by four persons
- any group of four persons associated in office or authority
See quadrumvirate in American Heritage Dictionary 4
(kwŏ-drŭmˈvər-ĭt)
noun A group of four people joined in authority or office, especially a government of four people: “[Chiang Kai-shek] was . . . the last survivor of the World War II quadrumvirate that included Roosevelt, Churchill and Stalin” (Newsweek).