Kate Middleton, taking a special break from maternity leave, arrived at the site of her 2011 royal wedding in a muted teal dress similar in cut to the one she wore to Meghan and Harry's wedding in May.
The former Suits star was the picture of elegance in a navy-black custom-made dress from Dior and Stephen Jones hat, while the mother-of-three was resplendent in a light blue coatdress from Alexander McQueen.
Later, Harry and Meghan, along with Prince William and Duchess Kate of Cambridge, appeared at a reception at the palace.
However, his great-grandmother the queen and her husband Prince Philip will not be among the guests, Kensington Palace said.
Hales out of first ODI against India due to side injury
Their last bilateral series' defeat came in India in January 2017, with only a freak one-off loss to Scotland in the interim. If the team management thinks of playing an extra pacer, Siddarth Kaul or Shardul Thakur might come into play.
Up next, Harry and Meghan are jetting off to Dublin, Ireland, for an official two-day visit to the country.
Meghan and Harry, who tied the knot at St George's Chapel nearly two months ago, looked completely in love and held hands as they arrived at the Chapel Royal, at St James' Palace, alongside the Cambridges, the Prince of Wales and the Duchess of Cornwall.
The Queen spoke proudly not only as the RAF's Air Commodore-in-Chief, but also as a citizen who remembered the Battle of Britain, and as a daughter whose father King George VI served with the RAF.
According to the post, the Duchess of Cambridge was christened on June 20, 1982, which just so happens to be the day before Prince William was born.
After a busy week in Scotland last week, the queen faced another busy week ahead in London, including a meeting with visiting President Donald Trump and first lady Melania Trump on Friday.
The RAF was formed with the amalgamation of the Royal Flying Corps (RFC) and the Royal Naval Air Service (RNAS) on 1st April 1918.