 Although Germanic settlers may have been present earlier, the West Saxons advanced from the south coast in the 5th Century and brought Swindon under their control after the Battle of Beranburgh, reportedly at Barbury Castle in 556.There is some possibility of another battle fought against the native Romano-Britons at Wanborough in 591.Claims have been made that a further battle was fought at Wanborough in 717 between Ceolred, King of Mercia, and Ine, King of Wessex, and the area was still in dispute in 825 as demonstrated by the Battle of Ellandun

The West Saxons built a farming community based on the top of Swindon Hill, with remains of wood-framed and Plaster huts found near to Market Square.