Named for the Persian king Darius I, the Great (550–486 B.C.), who became king after the death of Cambyses II and married two daughters of Cyrus II {see planet  (7209)}. His splendid palace in Persepolio was destroyed by Alexander the Great. Darius was defeated by the Greeks at the battle of Marathon in 490 B.C., and he died as he was preparing a new campaign against them. (M 30800) _ _.