130 million years ago, armoured dinosaurs roamed what is now southern England, parts of Europe and the USA. These were the Polacanthidae, and today their remains are becoming better known and understood. This book records the history of armoured dinosaur discoveries in the United Kingdom, from Mantell, Owen and Fox to the present day. It also reviews the important fossil remains that are housed in the UK national and private collections; remains that include some of the best preserved and most interesting armour ever found of these animals. The polacanthid taxa recovered from Lower Cretaceous rocks of Europe and the USA are also discussed, along with a new taxonomic (genus) name for the Horsham specimen.