Tony Robinson heads to the south-west corner of Wales and one of Britain's finest coastal paths to find out why Pembrokeshire feels so English, even though it's more than 100 miles from the border. With its numerous castles and a fine cathedral, there are sure signs the Normans stamped their mark over the area. Tony's four-day walk traces the story of their conquest of the county, which he discovers was very different from the knockout victory at Hastings, involving a long, fiercely fought struggle.