Claim: At least one King of the United Kingdom's first grandchild was Charles, Prince of Wales.
Evidence: Charles was born at Buckingham Palace as the first grandchild of King George VI and Queen Elizabeth.
George VI -LRB- Albert Frederick Arthur George ; 14 December 1895 -- 6 February 1952 -RRB- was King of the United Kingdom and the Dominions of the British Commonwealth from 11 December 1936 until his death.