The royal family's first Christmas since the death of Queen Elizabeth will be "hard".

Britain's longest-reigning monarch died in September, aged 96, and a former palace staffer believes that she will be on the minds of the royals when they gather at Sandringham.

The source told PEOPLE: "It will be hard, as the Queen was all they knew, like most of Britain.

"The first year is most difficult, as it is always the first of everything that you notice."

King Charles, his siblings and Prince William are all expected to gather at Sandringham over Christmas.

However, Prince Harry - Charles' youngest son - and his wife, the Duchess of Sussex, are not expected to join their family in the UK.

The royal couple's documentary series, 'Harry and Meghan', recently aired on Netflix, and in the show, Harry claimed that he was once "blocked" from spending time with the queen.

The 38-year-old prince and his wife knew late in 2019 that they wanted to start a new life overseas, and his grandmother was aware of their struggles and invited them to discuss the situation with her.

Harry said: "She knew that we were finding things hard, I had spoken to her many times about it.

"She said she had no plans for the week and said 'Why don't you come up and have tea, stay the night, you and Meghan'."

However, the couple were subsequently told by an aide that the meeting was cancelled because the queen was simple too busy to see them.

Harry recalled the queen saying: "I didn't know I was busy, I'm told that I'm busy. I've actually been told I'm busy all week."

Harry - who now lives in California with his wife and their children - added: "I was like, wow."