The first civilizations rose in the river valleys of the Nile, Mesopotamia, the Indus, and the Yangtse. Agriculture led to surplus food, which in turn led to trade centered in cities. These cities were founded on the use of tools and weapons made of wood, stone and clay. Copper, a soft but easily found and forged metal, soon replaced stone and wood in many tools and weapons. But copper was so soft that it was gradually replaced by a copper-tin alloy, bronze. Tin was rare and expensive, and the alloy was difficult to make, but it was so much harder than copper that the extra effort was worth it. It was with bronze that civilization moved out of the river valleys. Another advance came the Near East's way more dramatically when the steppe tribes introduced the chariot drawn by onagers and later small horses. Several ancient kingdoms, including the greatest, Egypt, were conquered by these chariot-borne barbarians. The Chariot would be the king of battle for over a millennium, until better trained infantry and cavalry swept it from the battlefield. With bronze weapons and chariots, the Great Kingdoms of the Near East swept all before them, until their societies began to fall apart and the predatory Sea Peoples savaged the Mediterranean, bringing a Dark Age that only Egypt and Assyria survived. By 1000 B.C. a new metal had spread from northern Europe to the civilizations of the Near East, Iron. Iron was hard to mine and difficult to smelt, but it could slice bronze with ease. At first it was so valuable that it was used only for jewelry, but soon there was enough around for its use in war. Assyria, a rising militarist state in what is now northern Iraq, swept into the vacuum left by the fall of the Great Kingdoms of the Bronze age, eventually conquering the whole of the Near East. To use this page, click on underlined text to access the various maps of The Pre-Classical Age.