Sultan Qaboos bin Said al-Said travelled to Leuven last month to receive medical treatment, booking a complete hotel in the historic inner city to make his stay more comfortable.
However, the sultan's treatment at UZ Leuven in Gasthuisberg was stopped "in mutual consent" after just a couple of days, earlier than planned. This fuelled rumours that he was in a bad way.
The sultan ruled Oman for about 50 years, which makes him the longest-serving head of state in the Arabic area. He had no children, but will be succeeded by his cousin Haitham ben Tarek.