Selflessness has characterized the efforts of doctors and nurses who have helped me and other family members in a time of uncertainty and anxiety due to illness, said the 76-year-old king in a pre-recorded speech broadcast by British media on Christmas Day.
The Christmas greeting struck a somber tone, as Charles and his daughter-in-law, the Princess of Wales, have received cancer treatment during the year. But the king was heartened by the support they had received "through care and comfort".
British healthcare staff have carried out extensive strikes and protests over the past year, among other things, in hopes of improving working conditions in the strained British healthcare system.
According to tradition, the royal family also greeted their subjects after the church service at the royal estate Sandringham near the North Sea coast.
The king's brother, Prince Andrew, was not present. The latest scandal surrounding Prince Andrew concerns his contacts with a Chinese businessman who has close ties to the Chinese Communist Party.