“I declare before you all that my whole life, whether it be long or short, shall be devoted to your service and the service of our great imperial family to which we all belong.” That was the pledge given by Princess Elizabeth on her 21st birthday in 1947; less than five years later, on 6 February 1952, she was called upon to fulfil that promise, when she acceded to the throne as Queen Elizabeth II. On Sunday, the country will commemorate the 70th anniversary of Accession Day, initiating the Queen’s Platinum Jubilee celebrations.