SOURCES OF HISTORY Historians need evidences to be able to reconstruct the historical past, whether on recent events or on the remote past. They call them sources of information. Those tests or traces that the past has left us, can be classified into four groups: - Written documents - Oral history - Material remains - Audio-visual documents 1- Written documents have always been an important source for the study of the past. But some documents could be difficult to understand, o incomplete, so they need special study. It is important to keep in mind that documents written at the same time of the events to investigate are called historical documents. For example, a letter written by José Artigas. Those documents that were prepared after the historical events are called historiographic documents. 2- But when we do not have written documents to reconstruct the past, either because they have disappeared or the events were prior to the invention of writing, the h...