Earth’s beginnings can be traced back 4.5 billion years, but human evolution only counts for a tiny speck of its history. The Prehistoric Period—or when there was human life before records documented human activity—roughly dates from 2.5 million years ago to 1,200 B.C. It is generally categorized in three archaeological periods: the Stone Age, Bronze Age and Iron Age.

From the invention of tools made for hunting to advances in food production and agriculture to early examples of art and religion, this enormous time—ending roughly 3,200 years ago (dates vary upon region)—was a period of great transformation.