This is a painting by the 17th-century artist Guido Reni. His Cleopatra is in contemporary clothes, but the presence of the asp is the clue to her identity. Cleopatra VII, Pharaoh of Egypt, supposedly killed herself in this way on August 12 in the year 30 B.C.E. The oldest source for this story, Strabo, tells us that she either used an asp or applied some kind of poison ointment. For other historical accounts and modern theories, see the "Death" section of the Cleopatra article at Wikipedia.