The Indian rupee is derived from the Rūpaya (silver is called rūpa in Sanskrit) a silver coin introduced by Sher Shah Suri during his reign from 1540 to 1545. Since this is around about the same time that the Spanish discovered silver at the Cerro Rico in Potosí, the silver value of the rupee maintained a stable relationship with gold right up until the early 1870s. From 1871, the value of silver depreciated relative to gold, due to the drop in demand for silver in the mints of Europe and North America, as those countries changed over to the gold standard. This had severe consequences for the rupee and it resulted in the fall of the Rupee. Following the Fowler report, India adopted the gold exchange standard in the year 1898, fixing the value of the rupee at exactly one shilling and four pence (1s 4d) sterling.