Ancient History encompasses all events and civilisations from the beginning of writing and recorded human history and extending as far as late antiquity. It covers all continents inhabited by humans during the period of c. 3500 BC – 1000 AD. Ancient History is generally categorised into three ages: the Stone Age, the Bronze Age and the Iron Age, with recorded history considered by most to begin with the Bronze Age. The start and end of the three ages varies between world regions. In many regions the Bronze Age is generally considered to begin a few centuries prior to 3000 BC, while the end of the Iron Age varies from the early first millennium BC in some regions to the late first millennium AD in other regions.