A Greek geometer and applied mathematician who lived at Syracuse, a Greek settlement on the coast of Sicily. He is famous both for his profound mathematical work and for his ingenious mechanical inventions, which at the end of his life he used to defend his city against the Romans during the Second Punic War.
When he discovered the hydrostatic principle—that a floating body of a given weight displaces a volume of liquid having an equal weight—he is reputed to have jumped from his bath and run naked through the streets shouting Eureka! (I have found it!)
Archimedes is credited with many brilliant mathematical discoveries, especially in properties of geometrical figures, areas and volumes of conics, and principles of trigonometry. (He is thought to have known Heron's formula several centuries before Heron.) He found areas of plane figures by the method of exhaustion, prefiguring modern integral calculus.
He was killed by a Roman soldier during the sack of Syracuse.