King Charles III's aim of a "slimmed-down" monarchy came in for scrutiny on Friday, as questions were asked about who will stand in for him while he goes into hospital.
The 75-year-old British head of state will undergo prostate surgery next week, forcing him to cancel public engagements.
At the same time, his daughter-in-law Catherine, Princess of Wales, 42, is recuperating in hospital after abdominal surgery.
Her Kensington Palace office said she is facing up to two weeks' convalescence as an in-patient, then several months' recuperation at home.
Her husband, heir to the throne Prince William, 41, has postponed some engagements, and was seen leaving the private London clinic Thursday.
The situation leaves three out of four of the royal family's most senior members out of action.
That has led to focus on the functions of the counsellors of state - members of the royal family who can officially carry out duties in the absence of the monarch due to overseas travel or illness.
Typically they have been the four most senior adults over the age of 21 in the line of succession.
But legislation passed by parliament in late 2022 now restricts those who can act as substitute to "working members of the royal family".
That effectively sidelines Charles's younger brother Prince Andrew and the king's younger son, Prince Harry, even though both remain counsellors of state.
In the legislation, Charles added his sister Princess Anne and other brother Prince Edward to the members of the royal family who can act for him.
Andrew stepped down from royal duties in 2019 after a disastrous television interview in which he defended his friendship with the late US sex offender Jeffrey Epstein.
He was later stripped of his honorary military titles and royal patronages after settling a US civil claim for sexual assault without admitting liability. He no longer performs public engagements.
Harry, now estranged from his family, has not been a working royal since 2020 when he moved to California with his wife Meghan and launched a barrage of criticism at the royal family.
"How prophetic Princess Anne's words now seem when she was asked ten months ago about the new king's plans to reduce the royal workforce," wrote royal commentator Richard Kay in the Daily Mail.
Questioned about the prospect of a "slimmed down" group of working royals, Anne had replied that it was a plan conceived when "there were a few more people around", adding: "It doesn't sound a like a good idea."