This two-coin set is one of the "historic" issues by the Royal Mint combining a newly released coin with a historic coin taken from circulation.
The set marks the 75th Birthday of HRH The Princess Royal (Princess Anne).
The mint says about the set:
"Managing a busy schedule of royal engagements alongside her passion for sport and horses, Her Royal Highness The Princess Royal has been an industrious member of the Royal Family since she was 18 years old. Over the years, her active lifestyle and tireless dedication to charitable organisations has seen her become one of most popular members of the Royal Family. As she continues to serve the Crown, this year, The Princess Royal celebrates her milestone 75th birthday, which we proudly commemorate with a UK coin."
The set contains a Crown-sized non-circulating £5 (five pounds) coin, and a coin issued in the year of birth of the princess - 1950, which is a circulated brass threepence. | 
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