Superbly set high upon its river cliff above the Wye, Chepstow still guards one of the main river crossings from southern England into Wales. Few castles in Britain tell the story of medieval fortification, from beginning to end, as does this mighty stronghold. It was probably the very first stone castle in the entire country, and was to see successive developments right through to the Civil War of the 17th century. Throughout the Middle Ages, Chepstow was the centre of military and administrative power in the Marcher lordship of Strigoil.