1977 marked the 25th Anniversary of Queen Elizabeth's accession to the throne. The Royal Australian Mint celebrated the event with the release of this circulated commemorative coin and proof. The reverse was designed by Stuart Devlin and features a ring of 25 crowns side by side to symbolise Queen Elizabeth II 25 years on the throne. The obverse featured Arnold Machin's portrait of HM Queen Elizabeth II.In 1989 the Royal AustralianMint reproduced the reverse design as part of the Masterpieces in Silver collection. This second type featured the updated Raphael Maklouf portrait of HM Queen Elizabeth II.