London, July 6 -- The youngest member of Britain's royal family, Archie Mountbatten-Windsor, is being christened Saturday in a private family ceremony at Windsor Castle.

The 2-month-old son of the Duke and Duchess of Sussex will be baptized in a private chapel at the castle by Archbishop of Canterbury Justin Welby, head of the Church of England.

He will wear a lace and satin christening gown - a replica of one made for Queen Victoria's eldest daughter - that was also used for his cousins Prince George, Princess Charlotte and Prince Louis.

Archie's aunt and uncle Prince William and his wife Kate were seen arriving at the castle before the christening on Saturday. Queen Elizabeth II is not expected to attend.

Parents Prince Harry and Me...