Samuel Eilenberg was a Polish-American mathematician who co-founded category theory and homological algebra.
Samuel Eilenberg (1970)
Saunders Mac Lane and Eilenberg at a conference in July 1992
Saunders Mac Lane, born Leslie Saunders MacLane, was an American mathematician who co-founded category theory with Samuel Eilenberg.
Saunders Mac Lane
MacLane and Samuel Eilenberg at a conference in July 1992