Offa was King of Mercia from 757 to 796 AD. His kingdom covered the area between the Trent/Mersey rivers in the North to the Thames Valley in the South, and from the Welsh border in the West to the Fens in the East.

Offa’s Dyke is a linear earthwork which roughly follows the Welsh/English boundary. It consists of a ditch and rampart constructed with the ditch on the Welsh-facing side, and appears to have been carefully aligned to present an open view into Wales from along its length. As originally constructed, it must have been about 27 metres wide and 8 metres from the ditch bottom to the bank top.

The Dyke appears to have been constructed in response to events in the border region involving the Princes of Powys, but whether it was intended as an agreed boundary, as a defensive structure with long lost additional fortifications, or for some other use, is not known.

When the dyke was constructed is also not known, but it is thought to have been started in about 785 AD and to have taken several years to build. The 9th Century history of the region suggests that the earthwork had only a short period of importance and was then abandoned.

The Offa’s Dyke path National Trail was opened in 1971. Some of the 177-mile (285 km) route either follows, or keeps close company with, the remnants of Offa’s Dyke. The path starts at the edge of the Bristol Channel near Chepstow and finishes at Prestatyn on the North Wales Coast. Do check the excellent Offa’s Dyke Association website to get information about accommodation and facilities. There are several good guidebooks to the path – I am using the Cicerone one.

Having walked the entire 870 miles of the Wales Coast Path, and as I am also walking the Cambrian Way with friends which goes south to north through the middle of Wales, it seemed rather tidy for me to also walk Offa’s Dyke. But like the way that I have approached these other long distance paths, my plan is to do it sporadically, starting with day walks and then working up to longer stints as I find myself further from home.