The sterling standard was established in England by Edward I in 1300 requiring all articles of silver to contain 11 oz., 2 dwt. (penny weight) of pure silver to 18 dwt. Copper alloy in a 12 oz. (troy) pound. This rigidly enforced law has remained in effect to the present except of the period from 1697 to 1720, when a higher grade of silver was required. This was called the Britannia standard. By an act of Parliament in 1697, all wrought silver had to be of 11 oz., 10 dwt pure silver 10 dwt. Copper alloy in 12 oz. (troy) pound. This somewhat softer grade of silver was mandatory until 1719/1720 when the act was repealed and the sterling standard restored; the Britannia standard became optional after that time.