One of the wealthiest monarchs in the world, President Sheikh Khalifa bin Zayed al-Nahyan of the United Arab Emirates, passed away at the age of 73.
Sheikh Khalifa had been president of the United Arab Emirates since 2004, but his role had been ceremonial since he underwent a stroke in 2014.
His half-brother, Mohamed bin Zayed al-Nahyan, is now responsible for state affairs.
The al-Nahyan family reportedly has a fortune of USD 150 billion (GBP 123 billion).
In addition to being president of the United Arab Emirates, Sheik Khalifa was also the ruler of Abu Dhabi, the oil-rich capital of the UAE’s seven emirates.
The news of his death came from the official WAM news agency.
The Ministry of Presidential Affairs has declared 40 days of mourning with flags half-masted as of Friday, and work has been suspended in the public and private sectors for the first three days.
Sheikh Khalifa became the second president of the United Arab Emirates in November 2004, taking over from his father as the 16th leader of Abu Dhabi.
During his first decade in office, he presided over a major reorganization of the federal and Abu Dhabi governments.
But after his stroke, he is seldom seen in public, though he continues to render decisions.
Under the constitution of the United Arab Emirates, Vice-President Sheikh Mohammed ben Rashid al-Maktoum, ruler of Dubai, will serve as interim president.
The Federal Council, composed of the rulers of the seven emirates, must meet within 30 days to elect a new president.