The North Wales seaside resort of Llandudno developed in the 1850s from a scatter of small settlements on the slopes of the Great Orme. In the Iron Age the defences of Pen Dinas hillfort and Roman coin hoards suggest local military conflict. Skirmishes are recorded from the times of the Vikings. In later centuries the focus for military activity stretches a mile or so down the Conwy Valley, to the castles of Deganwy and battles between Welsh and English. Llandudno became embroiled in the invasion of Edward I when he gave the Bishop of Bangor land on the Great Orme to build a 'palace'. This was sacked in Owain Glyndwr's revolt of the early 1400s. With the rise of Britain's empire copper was mined, partly to provide cladding for the wooden-hulled ships of her navy. By the twentieth century significant military training establishments were based in the area, as were prisoner of war camps and convalescent homes for military personnel. In 1915 a German U-boat attempted to pick up escaped POWs in Llandudno Bay. Specialist equipment for the Normandy landings was developed here and it became the new location for the Royal Artillery's Coast Artillery School and the Inland Revenue, a few of the many important features of the town's military heritage.