I have been walking along the Offa’s Dyke Trail, which runs north from the outflow of the River Wye into the Severn at Chepstow, as far north as Montgomery – some 110 miles. The dyke, and the trail, carry on to Prestatyn on the north coast of Wales, but I could only allow seven days away from my desk in County Durham. The purpose of the walk was to help with research for a book on the early history of the Kingdom of Mercia, whose most famous and conspicuously busy king, Offa, is said to have been responsible for commissioning the dyke some time in the late 8th century.
The dyke does its thing: magnificently, along river cliff and over mountain, sinuously winding across flood plain, steeply narrow valley and broad-domed hill – through sheep and cattle pasture, woodland, wheat field, water meadow, back garden and farm yard; past church and manor house, castle and river and from small village to small town. Just the idea of surveying this grand design – a frontier built less for defence than for the ‘performative choreography’ of power, as one archaeologist has put it – and without map or compass, blows the mind.
I duly took my pictures, admired the height of the bank and the depth of the ditch; appreciated its artfully sinuous line and switchback daring; wrote my notes and sweated the miles and the ascents and descents. At some point, reaching dyke fatigue, I became distracted by trees. Sometimes the gorgeous view from the dyke, always facing west towards Wales, was framed by giant veteran oaks or its line, drawn out ahead, was traced by a thumbnail sketch of distant hawthorn or hazel. Occasionally the trail’s distinct marker – an acorn inside a yellow arrow – was nailed to a Scots pine or an elm. Once in a while I stopped in my tracks to admire a lone specimen soaring from the lemony green canvas of a meadow and, once, the tree in question was a magnificent field maple (Acer campestris), Britains’ only native acer: I have never seen one so large, its rich velvet green leaves on their wine-red stalks fully fifty feet from root to tip, casting deep midsummer shade.
June, in a warm year such as 2022, sees the red flush coming onto sycamore ‘helicopters’; and I could not resist capturing the image. Here too were exotica – at least so far as a visitor from County Durham is concerned. We see hardly any small-leaved limes (Tilia cordata) up North – at least, no natives. Oliver Rackham waxed lyrical over the lime, or pry – its historical value as a timber and coppice tree; its status as a marker of ancient management. Backlit by the sun the heart-shaped leaves dance in a faint breeze like small parasols. Sweet Chestnut (Castanea sativa) are here too, in numbers reminiscent of Ben Law’s well-named Prickly Nut wood in Sussex, their massive saw-toothed leaves catching shafts of intense sunlight. They are a Roman introduction, predating Offa by half a millennium.
I saw and heard no sign of the active management of woodlands – no coppice; no rasp of chainsaw echoing in the distance; no evidence, even, of new planting. Offa’s trees are utterly timeless, like the broad whaleback and jutting scarp of the Black Mountains, the peeking spire of a medieval church or the toothy ruins of the odd border castle. And, equally eternal, the irresistible monument draws the walker on towards the horizon and beyond.
On one occasion we came into the welcome shade of a green lane, a tunnel of trees now only used by the odd tractor and the trail’s walkers, lined with oak and ash and a line of outgrown hazel, browsed up to a few feet from the ground by sheep and cattle but hardy enough to not mind them. Another surprise, though it shouldn’t have been, was coming upon a commercial cider apple orchard, through whose well-tempered avenues the trail ran for half a mile or so, on the edge of Herefordshire. June is also a perfect time to see the wayfarer tree (Viburnum lantana), a modest shrubby mass of green with firework bursts of white flowers looking almost like tardy May blossom.
King Offa was not, I suppose, much interested in trees as they perform their own seasonal choreography in the British countryside. For the purposes of making a visual statement to the world they would rather have got in the way. But his immense earthwork has learned to live with the trees that have colonised it over the centuries and, as an artless masterpiece of landscape architecture, those trees are as much a national treasure as the dyke itself.