Prehistory usually refers to the period of human history prior to the advent of writing, which marks the beginning of recorded history. More precisely, prehistory is the period from which no known written records (including later copies) have been preserved. In Egypt, prehistory would end around 3500 BC. In New Guinea, prehistory would end around 1900. Still earlier periods of time are usually known as geological history.

When did prehistory begin? People disagree. Some would begin it with Homo erectus, around 1.5 million years ago. Others would begin it around 40,000 BC, with the Cro-Magnons. If however, human prehistory is defined, as presumably it should be, as the pre-literate history of Homo sapiens sapiens then at least the matter can be resolved in principle, and the recent pace of progress in understanding the evolution of Homo sapiens suggests the answer will not be long in coming. Current best estimates are in the range of 100,000 to 200,000 years ago.

Prehistory is often subdivided by a three-age system:

• The Stone Ages:
  • Paleolithic -- Old Stone Age.
  • Epipalaeolithic -- characterised by the use of microliths, not distinguished by all scholars.
  • Mesolithic -- Middle Stone Age.
  • Neolithic -- Late Stone Age, usually referring to the beginnings of agriculture.
  • Chalcolithic or Eneolithic -- mixed stone and metal tools, not a period distinguished by all scholars.
• Bronze Age -- use of copper and/or bronze tools.
• Iron Age -- the Iron Age began around 2200 BC in Turkey and the Caucasus Mountains. It came later to other areas. It didn't come to Polynesia until the coming of the Europeans, between 1500 and 1750.