The Battle of Crogen took place in a field in Powys adjacent to Offa’s Dyke and marked by a 1200 year old oak tree. History has recorded this battle as occurring 1165 between a combined Welsh force that included Owain Gwynedd, his nephew, the Lord Rhys, and the sons of King Madog of Powys, for once fighting with Owain instead of against him. They were opposed by an invasion force led by King Henry II, who was attempting to curb the power of the Welsh. To that end, he brought the largest army the Welsh had ever faced: 30,000 men. Henry also hired upwards of 2000 woodcutters to cut a path through the forest. But when the English army tried to force its way through a gap in Offa’s Dyke, the Welsh rained thousands of arrows down upon them from the heights.
Even though the English did eventually manage to force their way through the gap, the effort cost them greatly. In the end, Henry failed to gain any ground in Wales, and the English remembered Crogen for centuries as a place of disgrace and defeat. To this day, the local people remember the field as the place the English were buried. The Oak Tree that marks it is labeled, “The Oak at the Gate of the Dead” and the gap in Offa’s dyke is called “Adwy’r Beddau”: the gap of the graves”.