They built their city out of the granite mountains of the North-Central Anatolian Mountain Range, using the natural landscape to build a thick wall along sheer cliffs to secure their city, home to more than 50,000. Their brutal army and their ambitions helped them build an empire that rivaled Egypt and Babylon. Their armies stretched their vast empire westward across Anatolia to the Aegean Sea, south eastwards through northern Syria, and then across the Euphrates River into the western fringes of Mesopotamia.