Prince William joined by Carole and Pippa Middleton at a Christmas concert

Prince William kicked off the holiday season with some of his closest friends on Wednesday evening (Dec. 4), including Princess Charlotte's godfather, Tom van Straubenzee and others for a night of festive carols. The traditional concert was a fundraiser for one of William's late friends.

His wife, the Duchess of Cambridge, stayed home with their two children, Prince George and Princess Charlotte, but William was also supported on the night by his in-laws, Carole Middleton and her daughter Pippa.

Prince William attended a memorial Christmas carol service.

The evening was held to raise money to benefit a cause very close to William's heart – the Henry van Straubenzee Memorial Fund. The charity, which has both William and his brother Prince Harry as patrons, was established in memory of Tom's brother, a friend of the princes who died in a car crash in 2002.

"We are both delighted to be patrons of Henry's memorial fund," the royals wrote in the evening's program. "Each year brings with it more news about the progress that this charity continues to make. This is largely down to the generosity and support of donors, many of whom are here tonight at this, the seventh Christmas carol service."

Henry became friends with the princes while attending Ludgrove prep school; he was a classmate of Harry's, while his older brother Thomas was friends with William, and the foursome were said to be inseparable growing up.

The prince was supported by Pippa and Carole Middleton.

The carol service has become an annual tradition for the royals to remember their late friend, although this year Harry was unable to attend due to his tour to Africa.

In just a few weeks, the Middletons are likely to reunite with their royal relatives as the families come together to celebrate Christmas. Last year, Carole, husband Michael, Pippa and brother James were welcomed by the Royal Family at Sandringham, and they are likely to attend again this year as they all celebrate Princess Charlotte's first Christmas.

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