The Assyrian Empire spanned four modern-day countries in northern Mesopotamia. It had a strong army and advanced technology that allowed it to conquer other nations. The Assyrians' climate and geography affected what they ate, wore, and their culture. They depended on agriculture along the Tigris River and invented many technologies like locks, keys, and the 360 degree circle. The Assyrians had a polytheistic religion with temples and rituals centered around gods like Ashur, Ishtar, and Adad.