Heidelberg was first mentioned in the archives of the monastery of Schönau in the year 1196 - although some of the incorporated districts are older - and the "Homo Heidelbergensis", who was found some miles south-east of Heidelberg refers to a past that is hundreds of thousands of years old. Later archaeological finds point to settlements dating from the Stone and Bronze ages. Celts lived in this area, Roman occupiers bridged the Neckar about 100 A.D., and in 260 A.D the invasion of the German tribe "Alemanni" ended a period of calm. 500 years later, Monasteries in the region became centres of Christian culture and the resettlement of this area began.