or Agha Muhammad Khan (both: ä'gä mūhäm'mäd khän) , 1742–97, shah of Persia, founder of the Qajar dynasty. He was emasculated by family enemies at the age of five. He was vigorous and able, but his cruelty is proverbial. In 1794, he captured and killed the last ruler of the Zand dynasty (see Iran) and ended his campaign with a wholesale massacre in Kerman. He became shah in 1796. Aga Muhammad resisted a Russian invasion and himself invaded (1795) Georgia. Hated by his subjects, he was finally assassinated. His nephew Fath Ali Shah succeeded him.