1981 AD., Great Britain, Elizabeth II, Royal Wedding commemorative, 25 New Pence, KM 925.

Great Britain, Elizabeth II, Royal Wedding commemorative, wedding of Prince Charles and Lady Diana Spencer, engravers: Arnold Machin (obverse) and Philip Nathan (reverse), 1981 AD.,
25 New Pence (1 Crown) (38,5 mm / 28,44 g), copper-nickel, mintage 26.773.000 , medal alignment ↑↑, reeded edge,
Obv.: D· G· REG· F· D· - ELIZABETH II , young second (decimal) portrait of Queen Elizabeth II facing right.
Rev.: H. R. H. THE PRINCE OF WALES AND LADY DIANA SPENCER / .1981. / PN , conjoined profile portraits of Charles and Diana facing left.
KM 925 .

The crown, originally known as the "crown of the double rose", was an English coin introduced as part of King Henry VIII's monetary reform of 1526 with the value of 5 shillings.
The first coins were minted in 22 carat crown gold, and the first silver crowns were produced in 1551 during the reign of King Edward VI. However some gold crowns continued to be made up until 1662. No crowns were minted in the reign of Mary I, but silver as well as gold coins were minted in the reigns of Elizabeth I, James I, and Charles I.
After decimalisation on February 15, 1971 a new coin known as a 25p (25 pence) piece was introduced. Whilst being legal tender and having the same decimal value as a crown, the 25p pieces were issued to commemorate events, e.g. 1972 was for the 25th wedding anniversary of Elizabeth II and Prince Philip. The 1977 issue was to celebrate Queen Elizabeth's silver Jubilee, the 1980 issue for the 80th birthday of Elizabeth, the Queen Mother and, in 1981, the coin was issued to celebrate the marriage of Lady Diana Spencer and Prince Charles. Crown sized coins continue to be issued for major Royal events. As the crown had been five shillings before decimalisation, the denomination continued as 25 pence for the first ten years. Four issues were made between 1971 and 1981. Further issues continue to be minted to the present day, initially with a value of twenty-five pence, and then, from 1990, with a value of five pounds. A characteristic of all of these four 25p versions is that they have no indication of value, whereas the later 5 pound coins all do.
Weight: 28.28 grams, Diameter 38.61 mm; circulation issues are in cupronickel (75% Cu 25% Ni) although proofs are known in silver of unknown fineness (probably sterling silver).