"We have the grandest monarchy in the world embracing right into its heart a family of humble origins," royal historian Robert Lacey tells PEOPLE
With a drive around her favorite Scottish estate, Queen Elizabeth rolled out the welcome mat for Princess Kate‘s family in a very public way on Saturday – thought to be the first time the Middletons have stayed overnight at Balmoral Castle.
The Queen was at the wheel of her Range Rover as she chauffeured Kate’s mom, Carole Middleton, from a picnic during a late summer getaway to the highlands hideaway of Balmoral. The families enjoyed one of their favorite pasttimes, a country shoot.
The following day, Carole and her husband Michael – who stayed with the Queen at Balmoral Castle – joined the royals for Sunday service at Crathie Kirk church on the estate.
Robert Lacey, royal historian and consultant to the upcoming Netflix series The Crown, says of having Carole in the front seat, “This clearly shows that the Queen is signaling her pleasure about the arrival in the royal family of humble origins.
“We have the grandest monarchy in the world embracing right into its heart a family of humble origins,” Lacey tells PEOPLE. “Next year is the centenary of when the royal family gave up its aristocratic name for the plainer name of Windsor – and that set the tone for what’s happened ever since. It is one reason why the British monarchy thrives and flourishes.
“It has always been the family’s strength to adapt to changing times.”
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Although the Middletons are not known to have spent the night at Balmoral until now, this isn’t the first time the families have come together for a shoot. In 2010 Carole was spotted on a hunting trip with Prince Charles at Balmoral. And one of the earliest pictures of Kate with Prince William was in December 2002 at the royal family’s Sandringham estate. Back then they were both students at the University of St. Andrews, and Kate was spotted standing next to William with his faithful Labrador, Widgeon, at their feet.
William has long held winter shooting parties at Sandringham, basing himself at Wood Farm, during his college years and afterward. It is thought that the Middletons have joined the traditional shoots alongside the royal family, including the Queen.
William, Kate and their kids Prince George and Princess Charlotte arrived at Balmoral late last week. The couple, who are in the final stages of planning their tour to Canada, will step out on Friday when they attend an engagement for their Heads Together mental health campaign.