On Tuesday 24 February 1981 the engagement of Prince Charles to Lady Diana was made official in an announcement by Buckingham Palace.
The Lord Chancellor Lord Maclean made the following statement :
"It is with greatest pleasure that the Queen and the Duke of Edinburgh announce the betrothal of their beloved son the Prince of Wales to the Lady Diana Spencer, daughter of the Earl Spencer and the Honourable Mrs Shand Kydd."
Prince Charles quipped that he was "delighted and frankly amazed that Diana is prepared to take me on", quipped Prince Charles, 32, while Diana shyly stated, "with Prince Charles beside me I cannot go wrong." Diana was 19 years old at the time.
source: BBC On This Day (video: goentertain )