Maria Puente

USA TODAY

Six decades of royal routine were interrupted Wednesday when Buckingham Palace suddenly announced Queen Elizabeth II, 90, and her husband, 95-year-old Prince Philip, would not be boarding their usual train to her Sandringham estate for their annual Christmas break.

Just a day after hosting the extended royal family for her annual Christmas lunch, the two had caught "heavy colds," and decided to put off traveling to Norfolk by train, Buckingham Palace said in a statement.

The royal photographers, who had assembled to document her departure from the palace, were told about 30 minutes before that she would not be going, according to British media reports.

At the time, her Royal Standard continued to fly over the palace, signaling that Her Majesty was still in the building.

The queen, her husband and most of her immediate family spend every Christmas at Sandringham, just as they spend every summer holiday at her Balmoral estate in Scotland. Strict adherence to routine has been part and parcel of the royal lifestyle since she ascended to the throne 64 years ago.

As the Express put it Wednesday, the sight of the queen and the Duke of Edinburgh boarding the 10:44 a.m. train from King's Cross station, traveling in a roped-off First Class carriage, and arriving at King's Lynn two hours later "heralds the start of Christmas for millions" of Britons.

Prince Philip has had more recent ailments than his wife but both are in relatively robust health for people in their 90s. Still, even mild colds can be difficult for people their age.

The palace did not say when they might be well enough to travel.

The travel plans changed a day after the palace announced that the queen would step down as royal patron on two dozen of her hundreds of charities, handing them over to other members of the royal family as she continues to surrender more of her public duties with advancing age.

Meanwhile, London is on high alert following a terrorist attack at a Christmas market in Berlin on Monday. In the wake of that, security officials announced Tuesday plans to close roads around Buckingham Palace for the daily Changing the Guard ceremony and create a steel security wall around the event, which remains London's top tourist attraction.