The queen's husband says he wants to slow down and enjoy his time without having to keep a full schedule.
Philip has said he needs to cut back his duties because he is tiring and also having problems with his memory.
He has been involved with numerous charities for years and has attended thousands of royal events with the queen.
The prince's many years of service were hailed by newspapers and politicians Friday as he prepared to host a lunch for a charity that helps the deaf.
The Royal Mint has struck a coin to mark his birthday and Philip will also receive a 62-gun salute.
