Why could the word empire apply to Hammurabi's rule of Babylon?

Hammurabi's rule of Babylon can be considered an empire due to his successful unification of various city-states and regions under a centralized authority, expanding Babylon's influence and control. His implementation of a comprehensive legal code, the Code of Hammurabi, helped standardize laws and governance, promoting stability and cohesion across diverse populations. Furthermore, his military conquests and diplomatic strategies solidified Babylon's dominance in Mesopotamia, establishing it as a formidable power in the ancient world.