Archaeological works conducted during construction of the Chalgrove to East Ilsley gas pipeline identified two large and thirty-two small sites. These were predominantly late prehistoric in date, with Iron Age deposits being the most abundant. A small amount of Neolithic and Bronze Age activity was recorded, and a single Saxon site was found. Very little Roman activity was encountered outside the two main sites. No medieval and only one postmedieval site was encountered, although many undated ditches and pits recorded during the watching brief were probably from these periods. The largest archaeological site encompassed three or four separate settlement areas. The second largest site appears to have been a single enclosed settlement, probably a farmstead, established in the early Iron Age and occupied until the early Roman period. The watching brief located sixteen datable smaller sites and a further sixteen sites containing only undateable features. The earliest features discovered were two early Neolithic pits. An earlier Bronze Age burial, probably a barrow, was found. The Roman road from Dorchester-on-Thames to Silchester was located. A single high status Saxon burial was discovered. One site contained 17th to 19th century domestic structures. Medieval or post-medieval furrows and field boundaries were identified at eight sites. Written by Tom Wilson with Paul Booth, Kate Brayne, Derek Cater, Hilary Cool, Rowena Gale, John Giorgi, Malcolm Lyne, Hilary Major, Gemma Martin, James Rackham, Stephen Rowland, Susan Tyler, Alan Vince and Tania Wilson.