Decimal Portrait Decimal Portrait - Although the switch to decimalisation did not happen until 1971, decimal coins entered circulation before then. The 5p and 10p pieces were introduced in 1968 to replace the existing shillings and florins. They were the same size and value as the pre-decimal coins, so were able to circulate together until D-Day in 1971. It was a useful first step in preparing the public for what was to come. To help the new coins stand out from the older currency, a new portrait of The Queen was commissioned. Designed by Arnold Machin RA, the new portrait showed The Queen wearing a tiara instead of a wreath. The tiara had been given to The Queen by her grandmother, Queen Mary. Like Mary Gillick before him, Machin avoided using a couped portrait cut off by the neck which had been the norm on coins issued earlier in the century. Interestingly, a modified version of Machins portrait has appeared on British postage stamps since 1967, which means it is probably the most reproduced image in history. 

• Issuer - United Kingdom
• Monarch - Elizabeth II
• Type - Standard circulation coin
• Years - 1968-1984
• Value - 1 Sovereign = 20 Shillings
• Currency - Pound sterling (1158-1970)
• Composition - Gold (.9167)
• Weight - 7.99 g
• Diameter - 22 mm
• Thickness - 1.5 mm
• Shape - Round