Meghan Markle and Prince Harry Reunite with Kate Middleton and Prince William for Commonwealth Day

Meghan Markle and Prince Harry made their last official royal appearance on Monday as they joined Kate Middleton, Prince William and the rest of the royal family for the annual Commonwealth Service at Westminster Abbey.

Meghan and Harry arrived to the service first by car. Kate and William followed close behind in a separate car. Unlike in years past, the two couples were not part of the Queen’s procession, and were instead led to their seats before the Queen, Prince Charles and Camilla, Duchess of Cornwall made their entrance.

As William and Kate took their seats in the front row, Meghan gave them a little wave as she and Harry smiled and said hello to the couple.

The Duchess of Sussex wore a green Emilia Wickstead dress with a matching fascinator from William Chambers for the event. She accessorized her look with one of her go-to bags from Gabriella Hearst and nude pumps from Aquazzura. The Duchess of Cambridge opted for a red coat dress from her go-to designer Catherine Walker & Co with a matching hat, red velvet clutch and heels.

The royal family reunion was four months in the making, as the two couples hadn’t been seen together since they stepped out for Remembrance Day events in November. Harry and Meghan made their return to the U.K. last week as they set out on a final round of royal engagements before they officially step down as working royals on March 31.

“They are on different paths now,” a source previously said of the two couples. “It’s just the reality of the situation.”

Harry’s grandmother Queen Elizabeth requested the Duke and Duchess of Sussex’s attendance at the Commonwealth Day event, which highlights the global network of 54 countries that make up the Commonwealth. Harry and Meghan will remain president and vice-president of the Queen’s Commonwealth Trust, which champions young leaders around the world.

RELATED: Prince Harry and Meghan Markle Just Revealed Major New Details About Their Royal Exit

The Cambridges and the Sussexes were joined by the monarch, Prince Charles and Camilla, Duchess of Cornwall for the service on Monday.

William, along with his father Prince Charles and grandmother Queen Elizabeth, were involved in the discussions surrounding Harry and Meghan’s exit, gathering at the monarch’s Sandringham estate in January for a meeting to “talk things through.”

Those close to the couple say both Meghan and Harry struggle with ongoing feelings of isolation from the rest of the family, with Harry’s friend Tom Bradby—who interviewed the couple for their emotionally candid October documentary—­describing them as “bruised and vulnerable.” At the same time, William and Kate, both 37, are moving further into their future roles as King and Queen.

RELATED: Meghan Markle and Prince Harry Have a Movie Star Moment in the Rain — See the Stunning Photo!

Harry and William were said to have unfinished business between them when the Duke of Sussex returned to Vancouver Island in Canada to rejoin with Meghan and their son Archie following the summit at Sandringham.

“They didn’t leave on good terms by any means, but they are both relieved that it’s over,” a family friend previously told PEOPLE.

RELATED: Prince William Had the Perfect Response When a Fan Said They Loved His Wife Kate Middleton

The royal brothers’ rift dates back to 2017, when William cautioned his younger sibling about moving too fast with Meghan, which in turn left Harry angry and hurt. Now that Meghan and Prince Harry have started their new lives — relocating to Canada with Archie amid their decision to step down as senior members of the royal family — there’s hope that Princess Diana’s sons will start to heal their relationship. A palace source said the brothers have been talking more in recent weeks.

RELATED: Meghan Markle Shares Sweet Update on 10-Month-Old Son Archie: He’s ‘Into Everything’

Meghan and Harry have been “enjoying a quiet life” in Canada, and they plan to spend more time in Meghan’s hometown of Los Angeles this summer.

Can’t get enough of PEOPLE‘s Royals coverage? Sign up for our free Royals newsletter to get the latest updates on Kate Middleton, Meghan Markle and more!

They are also looking forward to announcing plans for a charitable organization later this year.

“This decision [to leave] had been weighing on them for a long time, and they are relieved to have it done,” a friend told PEOPLE. “A weight has been lifted off their shoulders.”