Queen Elizabeth and Prince Charles were at Balmoral for the 20th anniversary of Princess Diana's death.

Queen Elizabeth

Queen Elizabeth

The 91-year-old monarch, Prince Philip and their son - who was married to the late Princess of Wales for 15 years from 1981 to 1996 - were spotted driving separate Range Rovers at the royal's Scottish residence on Thursday (31.08.17).

The royal trio were seen driving a convoy of the vehicles but it's not known of Charles' wife Camilla, the Duchess of Cornwall, is also at Balmoral.

Mourners paid tribute to Diana - who died on August 31 1997 in Paris following a car crash - at her former Kensington Palace home and online, including her friend Sir Elton John.

He shared a picture of the pair on Instagram and wrote: "20 years ago today, the world lost an angel. #RIP @ejaf (sic)"

The queen was at Balmoral with Diana's sons, Princes William, 35, and Harry, 32, when she died, and the monarch was slammed by some for remaining at her Scottish residence immediately after the princess' death.

But William recently insisted it was a tough decision for their grandmother to make.

He said: "I think it was a very hard decision for my grandmother to make. She felt very torn between being a grandmother to William and Harry and her queen role.

"Everyone was surprised and taken aback by the scale of what happened and the nature of how quickly it happened, plus the fact that she had been challenging the Royal Family for many years beforehand."

He recently revealed the queen removed all newspapers from the house to ensure he and Harry, who were 15 and 12 at the time, wouldn't read any news reports about their mum and would have "privacy to mourn".

He explained: "At the time my grandmother wanted to protect her two grandsons, and my father as well.

"Our grandmother deliberately removed the newspapers so there was nothing in the house at all so we didn't know what was going on.

"And back then, obviously, there were no smartphones or anything like that so you couldn't get your news, and thankfully at the time to be honest, we had the privacy to mourn and collect our thoughts and to have that space away from everybody.

"We had no idea that the reaction to her death would be quite so huge."