The Prehistoric series is about early humans, the world they lived in, and the lives they led. It spans the Paleolithic Era (the Old Stone Age) through the Iron Age; from about 3.3 million years ago to about 1,000 years ago; from when humans first used stone tools to just before they began writing their history. In broad strokes and vivid examples, the series describes where and how these early people lived, the tools they used, the challenges of everyday life, and the development of culture, art, religion, and civilizations. Each title includes a timeline of major events. The Iron Age was the last great prehistoric age. Iron tools made life easier, yet the Iron Age was a time of constant war. Chapters cover how Greece went through a Dark Age, how new forms of government began, how architecture became more complex, new religions formed, and money was invented. Each chapter includes attention-grabbing photos and fascinating facts. Sidebars go deeper, and prompts invite readers to think for themselves. A Timeline of the Iron Age gives a big-picture view of the era.