Protohistory is the period between prehistory and written history, during which a culture or civilization has not yet developed writing, but other cultures that have developed writing have noted the existence of those pre-literate groups in their own writings.

Protohistoric may also refer to the transition period between the advent of literacy in a society and the writings of the first historians. The preservation of oral traditions may complicate matters, as they can provide a secondary historical source for even earlier events. Colonial sites involving a literate group and a nonliterate group are also studied as protohistoric situations.

The term can also refer to a period in which fragmentary or external historical documents, not necessarily including a developed writing system, have been found. For instance, the Proto–Three Kingdoms of Korea, the Yayoi, recorded by the Chinese, and the Mississippian groups, recorded by early European explorers, are protohistoric.

In The Oxford Illustrated History of Prehistoric Europe, an article by Timothy Taylor stated:

Because of the existence in some but not all societies of historical writing during the first millennium BC, the period has often been termed 'protohistoric' instead of prehistoric. Of course, the understanding of the past gained through archaeology is broadly different in nature to understanding derived from historical texts. Having both sorts of evidence is a boon and a challenge.

— Timothy Taylor, The Oxford Illustrated Prehistory of Europe

In the abstract of a later paper on "slavery in the first millennium Aegean, Carpatho-Balkan and Pontic regions", Taylor, primarily an archaeologist, stated,

I have taken the rather unusual step of trusting what the classical authors tell us they knew.