The discovery of gold in the mid-nineteenth century led to the establishment of branch mints in Sydney, Melbourne and Perth. The Sovereigns and Half-Sovereigns minted there went on to circulate across the world alongside those struck in London. In 1910, Australia replaced British coins with a distinctive coinage of its own. At first these coins were struck in the United Kingdom but their production switched to the branch mints during the First World War. When Australia changed over to a decimal coinage in 1966, The Royal Mint was involved in the production of master tools and coins to assist the newly opened Royal Australian Mint in Canberra. The decimal coins feature an attractive series of wildlife designs by Stuart Devlin. More recently, in the early 1980s, The Royal Mint was again able to offer assistance by producing coins at a time when the supply of coins by the Royal Australian Mint was temporarily interrupted.