CNN —  

Meghan, Duchess of Sussex, was making her first appearance at a public engagement Saturday since the birth of her son, Archie Harrison Mountbatten-Windsor, at the traditional Trooping the Colour, a celebration of the Queen’s official birthday.

A royal source exclusively told CNN the duchess is expected to attend the traditional Trooping the Colour, a celebration of the Queen’s official birthday on Saturday.

Although the duchess is still on maternity leave, the royal source says this is a family moment, where many members of the royal family will be in attendance. Archie will not be among them.

According to the palace’s source, this is a separate affair from the duchess’ official duties of participating in a formal state visit.

Similarly, Catherine, the Duchess of Cambridge, also attended a previous Trooping the Colour during her maternity leave, but did not carry out any official duties.

The duchess and her husband, Prince Harry, welcomed baby Archie into the world last month.

The duchess shared a photo of baby Archie on the couple’s Instagram account on her first Mother’s Day last month.

Annual spectacle

More than 200 horses, 400 musicians and 1,400 officers, adored with their famous red jackets and black bearskin hats, will be taking part in the spectacular display on Saturday.

The monarch is technically the head of Britain’s armed forces, and would traditionally lead an army into war. The parade gives the Queen a chance to review and approve her army.

The Parade moves from Buckingham Palace and down the Mall to the House Guard’s Parade in Whitehall, with members of the Royal family traveling on horseback or carriage.

When the Queen was younger, she would ride side-saddle on horseback to greet the public. But in recent years, she travels by horse and open carriage.

The Queen inspects the troops at the Horse Guard’s Parade before riding back to Buckingham Palace at the head of her Guards. Once at the palace, the entire royal family will gather on the balcony to watch the colorful flypast by the Royal Air Force.

The event is also marked by a 41-gun salute in Green Park by the Horse Artillery.

The Queen’s real birthday is on April 21, but official celebrations always take place on June 10, and often for a whole weekend. The nation’s longest serving monarch turned 93 in April.

According to the Royal Family’s website, the Trooping of the Color has traditionally marked the official birthday of the British Sovereign for more than 260 years.

CNN’s Angela Dewan contributed to this report.