It's only a few times a year that the entire royal family is summoned by the Queen to Buckingham Palace. One of those occasions is today: the annual Christmas luncheon.

All members of the family are invited, including extended family that will not be attending Christmas at Sandringham. It's a big annual catch-up, and William and Kate introduced Prince George to many relatives for the first time!

VOTE: What should Kate wear on Christmas day?

The royal couple reportedly arrived for the luncheon 15 minutes later than the rest of the family. From what we've read of the Queen's strict rules of punctuality (and order of arrivals - senior royals last) we hope Wills and Kate didn't get a scolding! One look at little George surely would have melted away any annoyance at the Palace. Kate was dressed in red for the occasion, very fitting. We've tried to place the top Kate wore and while some have reported that it is her red Armani coat, we think it's more likely that it's a new piece for the holiday season (or possibly the Alexander McQueen dress she wore in 2012 -- below, second image from the left). More of Kate's red looks:

Kate Middleton red outfitsPhotos: Getty Images

They arrived in their Range Rover driven by Prince William, with little George in the back seat next to nanny Jessie Webbin. Notably missing from the lunch were Prince Harry (on his way home from the South Pole) and their cousin Princess Eugenie, who is currently living here in New York City.

Click through the gallery above to see Kate's best looks of 2013!