Justice League: A Better World
Checkmate is a government organization dedicated to covert operations. Its precursor is the group Agency led by Valentina Vostok . Harry Stein founded the organization under direction of and Task Force XX . Their missions are accomplished by special agents, named after chess pieces, around the world. They later became sanctioned by the United Nations. Their leaders include the Black King and Black Queen in charge of operations and the White King and White Queen in charge of intelligence.
The standard Checkmate operative was the Checkmate Knight.