The early pennies were struck from fine silver (as pure as was available). However, in 1158, a new coinage was introduced by King Henry II (known as the "Tealby penny") which was struck from 0.925 (92.5%) silver. This became the standard until the 20th century and is today known as sterling silver, named after its association with the currency. Sterling silver is harder than the 0.999 (99.9%) fine silver that was traditionally used and so sterling silver coins did not wear down as rapidly as fine silver coins. English coins were almost exclusively made of silver until 1344, when the gold noble was successfully introduced into circulation. However, silver remained the legal basis for the pound sterling until 1816.