The document summarizes why the Assyrians were great warriors around 900 BCE. It explains that their geography in a fertile valley near the Tigris River forced them to defend themselves, making them well-organized. As warriors, the Assyrians had advanced siege weapons and tactics like battering rams and tunneling to take cities. They also had new, strong weapons like iron which gave them military advantages over enemies. The Assyrian empire grew very large through conquest but this also made it difficult to govern and control, contributing to its eventual fall as enemies united against it.