The earliest was the Stone Age. The Stone Age is a period of prehistory that lasted from the beginning of human tool-making to the development of metallurgy. The Stone Age is divided into three periods: the Paleolithic, Mesolithic, and Neolithic. The Paleolithic is the longest period, and it is marked by the use of simple stone tools. The Mesolithic is a transitional period marked by the use of more advanced stone tools and the beginning of agriculture. The Neolithic is the final period of the Stone Age, and it is marked by the use of polished stone tools and the development of pottery. The Bronze Age is a period of prehistory that lasted from the development of metallurgy to the development of writing. The Bronze Age is characterized by the use of bronze, an alloy of copper and tin.