Ninurta, in Mesopotamian religion, city god of Girsu (Ṭalʿah, or Telloh) in the Lagash region. Ninurta was originally the Sumerian god of springtime thunder and rainstorms and of the plow and plowing and was later a deity of war. His earliest name was Imdugud, which means “rain cloud,” and his earliest form was that of the thundercloud envisaged as an enormous black bird floating on outstretched wings roaring its thunder cry from a lion’s head. With the growing tendency toward anthropomorphism, the old form and name were gradually disassociated from the god as merely his emblems; enmity toward the older unacceptable shape eventually made it evil, an ancient enemy of the god.
Ninurta was the son of Enlil and Ninlil (Belit) and was married to Bau, in Nippur called Ninnibru, queen of Nippur. A major festival of his, the Gudsisu Festival, marked in Nippur the beginning of the plowing season.