/*Buckingham Palace*/ said on Tuesday the family will mark /*Prince Philip's*/ milestone with a service at Windsor Castle's chapel and reception on June 12, two days after his actual birthday.
The occasion comes at a busy time for the 84-year-old queen. In the coming months, she will celebrate the April 29 wedding of grandson /*Prince William* and the July wedding of granddaughter /*Zara Phillips.*/
The palace said it had created a dedicated website, where well-wishers can peruse photos and leave Prince Philip a birthday message.
On his actual birthday on June 10, Prince Philip will perform official duties at Buckingham Palace.