How old was Prince Charles when he was invested as the Prince of Wales?

Charles, Prince of Wales (Charles Philip Arthur George; born 14 November 1948), is the eldest child and heir apparent of Queen Elizabeth II. Known alternatively in South West England as Duke of Cornwall and in Scotland as Duke of Rothesay, he is the longest-serving heir apparent in British history, having held the position since 1952.

Charles was created Prince of Wales and Earl of Chester on 26 July 1958. It was not until the age of twenty his investiture was conducted on 1 July 1969, when he was crowned by his mother in a televised ceremony held at Caernarfon Castle. He took his seat in the House of Lords in 1970 and made his maiden speech in June 1974. Charles also began to take on more public duties and founding The Prince's Trust in 1976.

Charles is the second-longest serving Prince of Wales, behind Edward VII, whose record he would surpass on 9 September 2017. He is the oldest and longest-serving heir apparent, the longest-serving Duke of Cornwall, and the longest-serving Duke of Rothesay. If he became monarch at present he would be the oldest person to do so; the current record holder is William IV, who was 64 when he became king in 1830.