According to ‘The Druids in time and space’, the texts mentioning Druids are drawn from wide tracts of territory over long spans of time. Classical texts describe them as philosophers, teachers, judges, the repository of knowledge and tradition, mediators between humans and gods. In later texts and the vernacular literature, they appear as mystics and magicians. It is probably best to regard them as a caste of intellectuals. The Classical texts mention Druids only in Gaul and Britain, while the vernacular sources tell of Druids in Ireland also. They may have been more widespread, however. It is probable that Druids existed in the 4th century bc and perhaps much earlier.