The King’s health is “heading in a very positive trajectory”, royal sources have said, as he marks the second anniversary of his accession to the throne.

The monarch, 75, attended a church service near Balmoral on Sunday to commemorate the anniversary of Queen Elizabeth II’s death, which also marks the start of his reign.

Charles’ second year as sovereign has been filled with health concerns, having been diagnosed with an unknown form of cancer earlier this year. He is said to be recovering well and is preparing for a his first major overseas trip to Australia and Samoa in the autumn.

“Health has to remain the number one priority, albeit heading in a very positive trajectory,” the royal source said.

It comes as his daughter-in-law the Princess of Wales, who was also diagnosed with cancer this year, is reportedly hoping to make a return to public life in the coming months.

Kate, 42, has made two official public appearances since her diagnosis – attending Trooping the Colour in June and presenting the Wimbledon men’s trophy in July.

According to The Times, it is understood she is hoping to join the royal family at the Cenotaph on Remembrance Sunday and host her Christmas carol concert.