Charles's rock Princess Anne takes it all in her dignified stride as ever

THE announcement shocked the nation, but within hours of the King's cancer news being made public, it was business as usual for the monarch's only sister.

- Matthew Dennison

The example she immediately set shows why Britain and the King need dependable Princess Anne more than ever.

At 11 am on Tuesday, the 73-year-old Princess Royal held a two-hour-long investiture at Windsor Castle.

Then she spent the afternoon in Nottinghamshire, visiting a healthcare centre, before going back for a London prizegiving ceremony.

It wasn't the first time the Princess had held an investiture nor was it a last-minute diary change: she had agreed to take on the ceremony due to the King's hospital treatment for an enlarged prostate.

But what was entirely characteristic was her willingness to step into the breach in support of a much-loved brother, just as she supported her mother, Elizabeth II.

For many years, the royal brother and sister have been Britain's hardest-working royals by a country mile. The workaholics inherited in full measure their parents' famed dedication to duty. Last year, the Princess pipped His Majesty to the top spot with 457 engagements against the King's 425. This year, for reasons no one would have wished, she may do so again.

Multiple engagements in a single day, sometimes necessitating helicopter flights between fixtures and more than one change of clothes, are not unusual.