 Settlement across the area seems to have become established during the Bronze Age according to various recovered artefacts and crop marks left by round barrows and burial mounds from that period.Iron Age remnants have not been detected until the Late Iron Age, with various local chieftain burials dated to the 1st Century BC gaining national prominence.The Belgae Celtic culture colonised much of South-Eastern England in the 1st century BC, with Welwyn in the area believed to have been settled by the Catuvellauni tribe.