Nimrud, Iraq. Vertical aerial photograph of the ancient tell near Noomanea village thought by local tradition to have been the city of Nimrod. Calah, or Kalhu, was the capital of the Assyrian Empire in the 9th and 8th centuries BC. It thrived from the 13th century BC until its destruction by the enemies of Assyria in the late 7th century BC. Archaeologists have been excavating here since the 1840s, notably Sir Austen Henry Layard.