'Edinburgh Castle, As It Was Before the Siege of 1573', 1890. During the 15th century the castle was used as an arsenal and armaments factory, its' defences were improved following the death of James IV in battle at Flodden Field in 1513. From "Cassell's Illustrated Universal History, Vol. III - The Middle Ages", by Edmund Ollier. [Cassell and Company, Limited, London, Paris and Melbourne, 1890. ]