These circulating commemorative coins celebrate the London 2012 Olympic Games, for which the Royal Mint released a series of coins representing various sports: Aquatics, Archery, Athletics, Badminton, Basketball, Boccia, Boxing, Canoeing, Cycling, Equestrian, Fencing, Football, Goalball, Gymnastics, Handball, Hockey, Judo, Modern Pentathlon, Rowing, Sailing, Shooting, Table Tennis, Taekwondo, Tennis, Triathlon, Volleyball, Weightlifting, Wheelchair Rugby and Wrestling.
The British decimal fifty pence (50p) coin - often pronounced fifty pee - is a unit of currency equalling one half of a pound sterling. It is a seven-sided coin formed as an equilateral-curve heptagon, or Reuleaux polygon - a curve of constant width, meaning that the diameter is constant across any bisection. This shape, which was revolutionary at the time, made it easily distinguishable from round coins both by feel and by sight, while its constant breadth allowed it to roll in vending machines.
The denomination was introduced in October 1969 with a large version of the coin; it was reduced in size in 1997, with the older coins being demonetised in 1998. The design of the new (smaller) type remained unchanged at that time, retaining Christopher Ironside's Britannia reverse. In 2008 though the reverse was changed to a design by Matthew Dent representing part of the Royal Shield.
The denomination has also been used extensively to issue one-year types of commemorative coins such as this one.
Twenty pence and fifty pence coins are legal tender only up to the sum of £10; this means that it is permissible to refuse payment of sums greater than this amount in 20p and 50p coins in order to settle a debt.
Coins issued in 2011 have now been in circulation for eight years.
Crowned mature head of Queen Elizabeth II facing right (effigy known as the "Fourth Portrait"). The Queen wears the "Girls of Great Britain and Ireland" diamond tiara, a wedding gift from Queen Mary (Her Majesty's grandmother) in 1947 - which she also has on the Machin and the Gottwald portraits.
In tiny letters below the head, the artist's initials IRB (for Ian Rank-Broadley).
Around the effigy is the monarch's legend and the date: ELIZABETH · II · D · G REG · F · D · 2011. Translated from Latin: Elizabeth the Second, by the grace of God, Queen, Defender of the Faith 2011.