Archaeological evidence suggests that the area of the bridgehead was not occupied from the early 5th century until the early 10th century. Environmental evidence indicates that the area was waste ground during this period, colonised by elder and nettles. Following Alfred the Great's decision to reoccupy the walled area of London in 886, new harbours were established at Queenhithe and Billingsgate. A bridge was in place by the early 11th century, a factor which would have encouraged the occupation of the bridgehead by craftsmen and traders. A lane connecting Botolph's Wharf and Billingsgate to the rebuilt bridge may have developed by the mid-11th century. The waterfront at this time was a hive of activity, with the construction of embankments sloping down from the riverside wall to the river. Thames Street appeared in the second half of the 11th century immediately behind (north of) the old Roman riverside wall and in 1931 a piling from this was discovered during the excavation of the foundations of a nearby building. It now stands at the base of the church tower. St Magnus was built to the south of Thames Street to serve the growing population of the bridgehead area and was certainly in existence by 1128–33.