The Bombay Mint, dating from 1672, is one of the oldest mints in Asia and produced coins for the East India Company and later administrations down to the present day. A gold refinery was established in 1918, expressly for the purpose of refining the South African gold. During 1919 and 1920 almost two million tolas of gold was refined. In addition to imports from the Rand mines, a vast quantity of gold was brought to the mint as a result of a wartime measure known as the Gold Import Act. A suitable structure, designated as a branch of the Royal Mint in London, was erected in the Bombay Mint compound, but completely isolated from the mint, for the specific purpose of coverting South African and recycled Indian gold into sovereigns. These were of the standard British Pattern, with George V on the obverse and the St George and Dragon reverse, but the letter I (India) was inserted in the exergue line above the date. Some 1,296,033 sovereigns were struck before the branch operation close in April 1919 for economic reasons. All of these sovereigns bore the date 1918.