Question: What did Eannatum use to keep the people of the time in line?
Sentence: Although short-lived, one of the first empires known to history was that of Eannatum of Lagash, who annexed practically all of Sumer, including Kish, Uruk, Ur, and Larsa, and reduced to tribute the city-state of Umma, arch-rival of Lagash.
Answer in sentence: no