But the wedding venue will not come as a surprise for many, as St George's Chapel has seen the wedding of many a royal in the past.
Mr Knauf added that the couple were "grateful to the Queen for granting permission for the use of the Chapel".
Meghan also said she intends to become a British citizen.
Kensington Palace said that Windsor Castle, a royal residence west of London, had become "a special place" for the couple.
He said the couple were delighted to be holding the wedding in the "beautiful grounds of Windsor".
Apple to launch standard edition handset in mid
Apple will launch a new version of its entry level iPhone SE in the first half of 2018, according to a new report from Taiwan. The SE 2 is being made in India and is expected to be ready for shipping in the first quarter of 2018 (January to March).
"They will be making sure it reflects who they are as a couple", he said. (In case you're wondering how all those Brits managed to take work off, their wedding day was actually an official bank holiday.) In other words, his brother's ceremony sounds like the exact opposite of what Prince Harry has in mind, and the monarchy has his back on that: Downing Street has said there are "no plans" for a bank holiday to mark the occasion.
They will visit Nottingham, where Prince Harry started the Full Effect programme in 2014 through The Royal Foundation.
"Bogart is now living with friends", Mr Knauf revealed.
Prince Harry and his fiancee also hope to allow members of the public to feel part of the celebrations and are considering how to make that happen.
Prince Harry was christened there, and his father Prince Charles held a blessing there after his civil wedding to his second wife, Camilla Parker-Bowles, in 2005. He said when she visited Buckingham Palace to meet the queen, "the corgis took to her straight away".
The palace confirmed the Queen will be a guest at Harry's wedding.