On the death of the Queen at her home in Balmoral on September 8, the Royal Family only carried out official duties where appropriate.
Members also dressed in black as a mark of respect for the late monarch when in public.
As of today, Royal Family members are carrying out their normal official roles in full after observing their own seven-day period of mourning.
William and Kate are due to spend the day travelling the length of Wales.
Queen Elizabeth II symbolically leads the lighting of the principal Jubilee beacon at Windsor Castle
Queen Elizabeth’s beloved corgis were “with her in the room” during her final hours at Balmoral Castle, reports claim.
They will first visit Holyhead in Anglesey and then travel to Swansea.
The royal couple had promised to visit at the earliest opportunity following the death of the Queen to begin “deepening the trust and respect” they have with the people of Wales.
The last official visit the pair made to Wales was as Duke and Duchess of Cambridge to Cardiff Castle in June to attend rehearsals for the Platinum Jubilee concert.
King Charles III carried out one official engagement during royal mourning by holding a telephone audience with the Chancellor Kwasi Kwarteng last Thursday on the eve of his tax-cutting, mini-budget.
The King travelled to Scotland soon after the Queen’s funeral last Monday. He could remain at his home of Birkhall into early October, following the tradition set by the late monarch.
Queen Elizabeth II would have spent about 10 weeks at her Scottish home during the summer months, returning to London around the time the autumn session of Parliament began.
Planning is likely to be under way for King Charles’ coronation.
The period of royal mourning comes to an end a day after Royal Mail announced four stamps featuring the Queen are being released in her memory.
The new stamps are the first to be approved by King Charles III and will go on general sale from November 10.
They will feature images of the late monarch through the years.
A photograph taken by Dorothy Wilding in 1952 to mark the Queen’s accession and coronation will feature on second-class stamps. The first-class stamp will include a photo taken by Cecil Beaton in 1968 in which the monarch is standing in her admiral’s cloak with her head tilted to the left.
On stamps costing £1.85, a portrait taken in November 1984 by Yousuf Karsh will appear and a photo taken by Tim Graham in 1996 while the Queen attended a banquet at Prague Castle during her visit to the Czech Republic will be the image on £2.55 stamps.
All four stamp images were released in the Golden Jubilee stamp issue in 2002 and were approved by the late Queen for issue that year.
Simon Thompson, Chief Executive of Royal Mail, said: “For the past 70 years every British stamp has been personally approved by Her Late Majesty, Queen Elizabeth.
A presentation pack of all four stamps will retail at £6.95 and is available to pre-order on the Royal Mail’s website.
The Royal Mail has also confirmed the King’s image will replace the Queen on new first and second class definitive stamps as well as all those of other values. Issues of special stamps will also feature a silhouette of King Charles.
Royal Mail said in a statement: “New stamps featuring King Charles will enter circulation once current stocks of stamps are exhausted.”
Royal Mail said: “In line with guidance from the Royal Household, to minimise the environmental and financial impact of the change of monarch, existing stocks of definitive stamps that feature the late Queen and the special stamps which use her silhouette, will be distributed and issued as planned. The launch dates of some of the special stamps may change.”
Source: EXPRESS CO UK