This is what the royals wear on Christmas Day

It's always fascinating to see how different families celebrate Christmas, even more so where The Firm are concerned, and that included what the royals wear on Christmas Day. And while we know the extensive list of what they eat for their Christmas dinner (pudding and brandy served no later than 2pm thank you very much), we're not as au fait with what they wear behind closed doors.

Well, as everything to do with the royal household, there are rules to follow. On Christmas eve, they take the lead from their German ancestors and open presents, which are traditionally joke ones.

The dress code for this is black tie, meaning tuxedos for the men, and floor-length gowns for the women. As it's likely to be post 6pm, the women will also be allowed to wear diamonds, though it's unlikely that they'd go all out with tiaras given that it's an intimate family gathering, but then again we've yet to receive an invite, so who knows?

On Christmas day, the family head en masse to St Mary Magdalene near Sandringham House for the morning service. For this, ladies always wear hats, and dress conservatively, especially as the weather is so cold. Last year, both Meghan and Katie opted for tonal dressing - Kate in a berry red button-up coat with matching velvet headband and suede pumps, and Meghan in black knee high boots, midi dress and black coat, with a pillbox feather hat, and accessorising with a Victoria Beckham bag.

They traditionally wear little jewellery, as it's still early in the day, though they sometimes adorn their coats with a brooch, as the Duchess of Cambridge and the Queen did last year. The Queen also often wears her signature bright colours.

Then for Boxing Day, it's back to casual - well, the royal family's take on casual. As they often go shooting, they will be wearing something like wellies and Barbour jackets, and the Queen often wraps her head in a patterned scarf.

Keep scrolling to see what the royals wear on Christmas Day, from Princess Diana to Kate Middleton.

Diana At Windsor

Princess Diana

Diana, Princess of Wales (1961 - 1997), chatting with Prince Edward, following a Christmas Day service at St George's Chapel, Windsor, UK, 25th December 1981. (Photo by Jayne Fincher/Princess Diana Archive/Hulton Royals Collection/Getty Images)

The Queen and family

Prince Andrew, Duke of York, Queen Elizabeth II, Diana, Princess of Wales, wearing a red military style coat designed by Piero de Monz, a black velvet crowned hat designed by Marina Killery, a Russian style black muff and black patent boots, Anne, Princess Royal and Peter Phillips leave St Mary Magdalene Church after attending the Christmas Day service on December 25, 1985 in Sandringham, United Kingdom. (Photo by Anwar Hussein/Getty Images)

Princess Diana

Diana, The Princess of Wales, attends The Christmas Day Service, at St Georges Chapel, Windsor Castle, on December 25, 1987, in Windsor, United Kingdom . (Photo by Julian Parker/UK Press via Getty Images)

British Royals

Queen Elizabeth, The Queen Mother (1900-2002), Peter Phillips, Prince Harry, Diana, Princess of Wales (1961-1997), Prince Andrew, Duke of York, and Sarah, Duchess of York and Prince William attend the Christmas Day service at St Mary Magdalene Church on the Sandringham estate in Norfolk, England, 25th December 1990. (Photo by Princess Diana Archive/Getty Images)

Princess Diana

Prince Harry and his mother Diana, Princess of Wales (1961-1997), wearing a blue and turquoise suit by Catherine Walker, with a matching hat, attend the Christmas Day church service at St Mary Magdalene Church in Sandringham, Norfolk, England, 25th December 1991. (Photo by Princess Diana Archive/Getty Images)

Diana, Princess of Wales (1961-1997), wearing a red coat with a black hat, Zara Phillips, Prince Andrew, Duke of York, Prince Edward, Peter Phillips and Prince Charles attend the Christmas Day church service at St Mary Magdalene Church in Sandringham, Norfolk, England, 25th December 1993. (Photo by Princess Diana Archive/Getty Images)

Princess Diana

Princess Diana holding flowers and Christmas presents from members of the crowd gathered after Christmas Day service at Sandringham Church (Photo by Tim Graham Photo Library via Getty Images)

Princesses Eugenie and Beatrice

Princess Eugenie (L), Prince Andrew (C) and Princess Beatrice (R) arrive along with other members of the British Royal family to attend a Christmas Day service at Sandringham Church December 25, 2002 in Sandringham, United Kingdom. (Photo by Scott Barbour/Getty Images)

Prince William and Kate Middleton

Arriving to church in 2013.

The Royal Family

Queen Elizabeth II leaves church with Prince William, Duke of Cambridge, Catherine, Duchess of Cambridge, Prince Philip, Duke of Edinburgh, Prince Charles, Prince of Wales and Prince Harry during the Christmas Day church service at Sandringham on December 25, 2014 in King's Lynn, England. (Photo by Danny Martindale/WireImage)

The Queen

Queen Elizabeth II attends a Christmas Day church service at Sandringham on December 25, 2015 in King's Lynn, England. (Photo by Chris Jackson/Getty Images)

The Cambridges

Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge, Prince George of Cambridge and Princess Charlotte of Cambridge arrive to attend the service at St Mark's Church on Christmas Day on December 25, 2016 in Bucklebury, Berkshire. (Photo by Andrew Matthews - WPA Pool/Getty Images)

Kate, William, Meghan and Harry

Attending Christmas Day Church service at Church of St Mary Magdalene on December 25, 2017 in King's Lynn, England.

Queen Elizabeth II

Queen Elizabeth II attends Christmas Day Church service at Church of St Mary Magdalene on December 25, 2017 in King's Lynn, England. (Photo by Chris Jackson/Getty Images)

Prince Charles, Prince of Wales with Prince William, Duke of Cambridge, and Catherine, Duchess of Cambridge, Prince Harry, Duke of Sussex and Meghan, Duchess of Sussex attend Christmas Day Church service at Church of St Mary Magdalene on the Sandringham estate on December 25, 2018 in King's Lynn, England. (Photo by Mark Cuthbert/UK Press via Getty Images)

The Queen

On Christmas Day 2019

The Cambridges

On Christmas Day 2019

Princess Beatrice and Edoardo Mapelli Mozzi

On Christmas Day 2019

Princess Eugenie and Jack Brooksbank

On Christmas Day 2019