The chapel has sentimental meaning for the family - it's where Kate Middleton received communion before her wedding in April 2011, and it is also where the coffin of Princess Diana lay before her funeral in 1997. The now Duchess of Cambridge was christened on June 20, 1982, just one day before the birth of her husband, Prince William.
On May 19, before she had even confirmed she was expecting, Pippa seemed to be glowing at Meghan Markle and Prince Harry's wedding in a mint green and patterned silk dress.
Welby, who will baptize the baby by pouring holy water from the River Jordan over his head, said the event would be "very nerve-wracking" but "a great privilege".
Britain's Prince Harry and Meghan, Duchess of Sussex.