The former King of Greece, Constantine II, is being treated in a hospital after contracting Covid-19.
Constantine, who was King of Greece from 1964 to 1973, is fully vaccinated against coronavirus.
He was first admitted to hospital on January 8 and is said to be in good health.
The 83-year-old was last in hospital just under a month ago when he was found to have had a stroke.
He has suffered from poor health for several years. In 2018, he was treated for a stroke and in recent times, he has been seen using a wheelchair on rare public outings.
Constantine II became King of Greece in 1964 but was forced into exile and deposed in 1973. He lived for many years in London with his wife, Anne-Marie, and their five children before returning to Greece in 2013.
The family home is now at Porto Cheli. Constantine’s last appearance was in October when he was seen at wedding celebrations for his youngest child, Prince Philippos, and Nina Flohr.