Prince Harry and Meghan, the Duke and Duchess of Sussex, have arrived at St. Paul’s Cathedral, marking the first time the couple has appeared publicly with the royal family in two years.

For the occasion, Meghan wore a Dior Haute Couture trench coat and skirt with matching hat and gloves, and Harry wore a tailored black dress jacket featuring his military medals and pinstripe pants. They were greeted by a guard of honor and then the Very Reverend Dr. David Ison on the cathedral's western steps.

The Sussexes stepped down from their roles as senior working members of the royal family in 2020 and later moved to California, where they live with their two children.

The couple watched the Trooping the Color parade Thursday alongside other royal family members at Buckingham Palace, but did not appear publicly.

The British royal family and more than 400 invitees – including government and faith leaders, teachers, military members, and COVID-19 frontline workers – are gathering at a National Service of Thanksgiving to celebrate Queen Elizabeth II’s 70 years on the throne.

The 96-year-old queen will not attend the service after experiencing “some discomfort” at Thursday’s Trooping the Color parade, according to Buckingham Palace.

Other senior royals are expected to attend, including three of the queen’s four children – Princes Charles and Edward and Princess Anne. The queen’s son, Prince Andrew tested positive for COVID-19 and will not attend, a royal source told ABC News.

The service – led by the Very Reverend Dr. David Ison – is being held at St. Paul’s Cathedral in London, which also hosted services for the queen’s Silver, Golden and Diamond Jubilees.

The service will include readings from the Bible, prayers and hymns that will “give thanks for the Queen’s reign, faith and lifetime of service,” according to the palace.

The Royal Marines’ band and trumpeters from the Royal Air Force and the Household Cavalry, which also performed at Prince Philip’s funeral, will play before and after the service.

A new song, titled “By Wisdom” and composed for the Platinum Jubilee, will also be performed.

Queen Elizabeth II and her grandson, Prince William, joined forces Thursday night for a lighting ceremony symbolizing the impact the queen has had around the world.

The queen appeared outside of Windsor Castle and touched a symbolic globe that set off a chain of lights to London, where William stood outside of Buckingham Palace.

There, the light landed at the “Tree of Trees,” a sculpture made of hundreds of indigenous British trees and plants. The tree is the symbolic culmination of The Queen’s Green Canopy, an initiative for the Platinum Jubilee that invited people across the U.K. to plant a tree.”

“Placing the ‘Tree of Trees’ at the heart of the beacon lighting reflects the Royal Family's long history of championing environmental causes and will pay a fitting tribute to Her Majesty’s 70 years of service to the nation,” Buckingham Palace said in a statement.

As the queen and William were participating in the beacon lighting ceremony, more than 1,500 beacons were set to light up across the U.K. and Commonwealth countries and territories.

Queen Elizabeth II will miss out on what was expected to be one of the highlights of her Platinum Jubilee, a National Service of Thanksgiving in her honor.

The 96-year-old queen will not attend Friday’s service at St. Paul’s Cathedral in London, Buckingham Palace announced.

“The Queen greatly enjoyed today’s Birthday Parade and Flypast but did experience some discomfort,” the palace said in a statement. “Taking into account the journey and activity required to participate in tomorrow’s National Service of Thanksgiving at St Paul’s Cathedral, Her Majesty with great reluctance has concluded that she will not attend.”

The queen, “would like to thank all those who made today such a memorable occasion,” the statement concluded.

The palace has previously said the queen suffers from “episodic mobility problems.”

She appeared in good spirits Thursday while watching the Trooping the Color parade and the military flypast from the balcony of Buckingham Palace.

Thursday's Trooping the Color though marked the first time in her 70-year reign that Elizabeth has given the royal salute from the palace’s balcony. Her oldest child and heir, Prince Charles, took the royal salute on the parade ground and inspected the troops in her place.