Pre-Historic

Pre-Historic or Prehistory (meaning "before history", or "before knowledge acquired by investigation") is the span of time before recorded history or the invention of writing systems. Prehistory refers to the period of human existence before the availability of those written records with which recorded history begins. More broadly, it can refer to all the time preceding human existence and the invention of writing.

The notion of "prehistory" began to surface during the Enlightenment in the work of antiquarians who used the word 'primitive' to describe societies that existed before written records. The first use of the word prehistory in English, however, occurred in the Foreign Quarterly Review in 1836.

The term "prehistory" can refer to the vast span of time since the beginning of the Universe, but more often it refers to the period since life appeared on Earth, or even more specifically to the time since human-like beings appeared. In dividing up human prehistory, prehistorians typically use the three-age system, whereas scholars of pre-human time periods typically use the well-defined geologic record and its internationally defined stratum base within the geologic time scale.

The three-age system is the periodization of human prehistory into three consecutive time periods, named for their respective predominant tool-making technologies: the Stone Age, Bronze Age, and Iron Age. This system emerged during the late nineteenth century in the work of British, German and Scandinavian archeologists, antiquarians and anthropologists. Another division of history and prehistory can be made between those written events that can be precisely dated by use of a continuous calendar dating from current and those that can't. The loss of continuity of calendar date most often occurs when a civilization falls and the language and calendar fall into disuse. The current civilization therefore loses the ability to precisely date events written through primary sources to events dated to current calendar dating.