King Bhumibol Adulyadej of Thailand made a rare public appearance on Sunday, leaving a Bangkok hospital to visit his palace in Bangkok, marking the first time he has left the hospital since he was admitted last year. His trip to the Chitralada Palace comes after an announcement from the Royal Household Bureau revealed Sunday that he had been undergoing treatment recently for a fever, lung infection and knee problem, according to the International Business Times.

"Currently, the king's fever has eased but his breathing is occasionally faster than normal, while his pulse and blood pressure are normal," the statement read.

King Bhumibol, the world's longest-serving monarch, was admitted to Sirriaj Hospital in October and had surgery to remove his gallblader. Prior to his reemergence from the hospital, he was last seen in September and missed his Dec. 5 speech marking his birthday celebration for the second year in a row. 

His public outing was brief, however, and he returned the same day, according to Reuters.

"His Majesty will go to the Chitralada Palace for a change of atmosphere and will return today," said a palace official speaking on the condition of anonymity.

The King is still a highly revered figure in Thailand despite his lack of presence. Though he has no formal political role, he is regarded as a stabilizing figure for Thailand, with many citizens saying they'd be lost without him, according to the Associated Press.

"I don't know what to think," banker Thaweewat Chongsuanoiy. "He has been the person that holds the people together; without him, people would be lost."

His declining health and in recent years has been a consistent source of political instability in Thailand, where the military took power in a coup in May 2014. Adding to these problems are fears over King Bhumibol's succession. The heir apparent, Crown Prince Vajiralongkorn, is widely unpopular.