During the American war of independence and the Napoleonic wars, Bank of England notes were legal tender, and their value floated relative to gold. The Bank also issued silver tokens to alleviate the shortage of silver coins. In 1816, the gold standard was adopted officially, with silver coins minted at a rate of 66 shillings to a troy pound of sterling silver, thus rendering them as "token" issues (i.e. not containing their value in precious metal). In 1817, the sovereign was introduced, valued at 20 shillings. Struck in 22‑carat gold, it contained of gold and replaced the guinea as the standard British gold coin without changing the gold standard. In 1825, the Irish pound, which had been pegged to sterling since 1801 at a rate of 13 Irish pounds = 12 pounds sterling, was replaced, at the same rate, with sterling.