Queen Elizabeth II and Kate Middleton have an upcoming royal engagement together.

According to Carly Read, a journalist for Express, the Duchess of Cambridge and Her Majesty will have a “rare” solo royal engagement seven years after their first one, joining forces on March 19 when monarch officially opens the Bush House, which was previously BBC World Service headquarters. The place is currently leased by Kings College London, of which Queen Elizabeth is a patron.

Queen Elizabeth II and Middleton had their first solo engagement together in 2012. During the outing, they were seen chatting politely. Prince William’s wife was photographed laughing as the Queen appeared to crack a joke.

The Queen and Duchess of Cambridge have grown closer over the years. In fact, they have reportedly become allies and have been seen together in various royal engagements, along with the other members of the Firm.

On Tuesday, the Duke and Duchess of Cambridge joined Queen Elizabeth II’s reception at Buckingham Palace for Prince Charles’ investiture. Also present in the event were the Duke and Duchess of Sussex, Camilla Parker Bowles, Princess Anne and more.

According to reports, Queen Elizabeth II reportedly initially had grave concerns about Middleton’s partying habits and lack of a fulltime job when she was still dating Prince William. However, she slowly warmed up to Prince William’s wife over time.

Queen Elizabeth II has given a lot of things to Middleton, recognizing her importance to the future king. She gave Middleton a girlfriend status, protected her from scandals, helped her prepare for the royal life that awaits her and also encouraged her to support charities to improve her reputation.

There were also reports that the Queen turned to Middleton for support amid Meghan Markle’s issues. Her Majesty was reportedly furious that she has to spend her twilight years mopping up the pregnant duchess' “horrendous headlines” as she recklessly toys with the royal family’s reputation.

Ashley Pearson said on Amazon Prime’s documentary “William & Kate: The Journey” that Queen Elizabeth II is “very fond” of Middleton’s “middle-class values.” She also likes how close Prince William’s wife is to her family.

On the other hand, Markle has a dysfunctional relationship with her family. She’s not on speaking terms with her dad and siblings. In fact, no one from her father’s side was present when she married Prince Harry.