Wat's Dyke - Dating Controversy

Dating Controversy

The dyke was previously thought to date to the early 8th century, constructed by Aethelbald king of Mercia who reigned from 716 to 757. Aethelbald's successor, Offa, built the dyke which carries his name sometime during his reign (757 to 796).

Excavations in the 1990s at Maes-y-Clawdd near Oswestry uncovered the remains of a small fire site together with eroded shards of Romano-British pottery and quantities of charcoal, which have been dated to between 411 and 561 AD (centered around 446 AD). This evidence would seem to place the building of the dyke in the era of the post-Roman kingdom whose capital was at Wroxeter (just south of modern day Shrewsbury) about 10 miles to the east.

The dating of the fire site and hence the dyke has been disputed, and it has been suggested that owing to the difficulties inherent in radiocarbon dating, this single date cannot be trusted and also that the dyke could easily have been built on top of the fire site at a later date.

Excavations in 2006 suggested a much later date of 792-852, and the earlier date is now thought to relate to a fire site which preceded the dyke. A likely context for construction is the 820s, when the Mercian king Coenwulf was fighting against a resurgent Welsh threat.