Sheikh Khalifa, U.A.E. Ruler, Is Dead at 73

The ailing ruler of the United Arab Emirates, Sheikh Khalifa bin Zayed Al Nahyan, a key figure in his country’s history and one of the world’s richest monarchs, died on Friday, the state-run Emirates News Agency reported. He was 73.

No cause of death was given, but Sheikh Khalifa had a stroke in 2014 and subsequently stepped back from many of his public duties. The government announced that government offices and private businesses would close for three days beginning Friday and that a 40-day mourning period would be observed across the Persian Gulf nation.

Sheikh Khalifa became the United Arab Emirates’ head of state after the death of his father in 2004 and held an array of weighty titles, serving as the country’s president; the prince of Abu Dhabi, the emirate of its capital city; and the head of its armed forces, investment fund and petroleum council.

But his public appearances grew increasingly rare after his stroke, leaving his younger half brother, Mohammed bin Zayed Al Nayhan, the crown prince of Abu Dhabi, to act as the de facto head of state.

It was widely expected that Sheikh Mohammed would succeed Sheikh Khalifa as the ruler of the United Arab Emirates, but no information about the formal succession process was immediately available.

The United Arab Emirates is a federation of seven emirates led by Abu Dhabi that also includes Dubai, a city famous for its futuristic architecture and reputation as a playground for the rich.

It is a close partner of the United States, and its military has fought alongside Americans in Afghanistan and elsewhere. Much of its wealth comes from oil and gas, although it has used that wealth better than other rich Persian Gulf countries to diversify its economy by bolstering tourism, financial services and other sectors.