Despite a long history of excavation and academic research no clear date (beyond ‘post-Roman’) has been produced for the construction of the monumental phases of the four Cambridgeshire ‘Anglo-Saxon’ Dykes. However, recent work along the westernmost of these, the Bran Ditch, has dated the initial phase of construction to the Early Iron Age. Three parallel ditches, on the same alignment as the Bran Ditch, were dated to the Early Iron Age through ceramics, radiocarbon and stratigraphic/spatial relationships. Two triple-ditched alignments are already known further west, one already dated to the Middle Iron Age. These early alignments may have functioned as both territorial boundaries, crossing the Icknield/Ashwell belt, and as routeways at the edges of these territories – both long-distance and between upland and lowland pasture. Two new triple-ditch alignments have been recorded in the gaps between the monumental ‘Saxon’ Dykes, further tying them in to the Iron Age boundaries to the west.