Prince Harry has said he is "delighted" at his brother's engagement, welcoming Prince William's fiancee Kate Middleton as the "sister" he had always wanted.
In a statement released through his press spokesman, Harry said: "I am delighted that my brother has popped the question! It means I get a sister, which I have always wanted."
The Prince of Wales says he is "thrilled" by the engagement, while his wife the Duchess of Cornwall said the news was "wicked".
Speaking at his Poundbury model village in Dorset, the Prince joked: "They have been practising long enough."
When congratulated by a member of the public, he said: "It makes me feel very old. Thank you very much."
His sentiments were shared by Miss Middleton's father Michael and mother Carole.
Mr Middleton said: "I would just like to say that Carole and I are absolutely delighted by today's announcement and thrilled at the prospect of a wedding some time next year.
"As you know Catherine and Prince William have been going out together for quite a number of years which has been great for us because we have got to know William very well.
"We all think he is wonderful and we are extremely fond of him. They make a lovely couple, they are great fun to be with, and we've had a lot of laughs together.
The Duchess of Cornwall added that news of Prince William's engagement was "absolutely wonderful". On her way out of an engagement at a London theatre, where the musical Wicked is staged, Camilla said: "It's the most brilliant news. I'm just so happy and so are they. It's wicked."