The United Arab Emirates’ long-ailing ruler, Sheikh Khalifa bin Zayed Al Nahyan, has died aged 73, the government’s state-run news agency has announced Khalifa, the president of the UAE, oversaw much of the country’s blistering economic growth and his name was immortalised on the world’s tallest building, the Burj Khalifa, after bailing out debt-crippled Dubai during its financial crisis more than a decade ago. The UAE’s ministry of presidential affairs announced a 40-day period of mourning and a three-day suspension of work in all ministries and the private sector beginning on Friday, including flags to be flown at half-staff. He had long ceased having involvement in the day-to-day affairs of ruling the country. Instead, his half-brother, Abu Dhabi’s Crown Prince Mohammed bin Zayed, was seen as the de-facto ruler and the decision-maker of major foreign policy decisions, such as joining a Saudi-led war in Yemen and spearheading an embargo on neighbouring Qatar in recent years. There was no immediate announcement about a successor, although Mohammed bin Zayed is anticipated to claim the presidency. Khalifa, who has rarely been seen in official photos or at public events for years, succeeded his father, the UAE’s founder, Sheikh Zayed, in 2004. He suffered a stroke and underwent emergency surgery a decade later, though officials did not release the news until the following day. He has largely been out of public sight ever since. In 2017, 2018 and 2019, Emirati state media published rare photographs and video of Khalifa. In the latest images, Khalifa wore white sneakers and a white traditional robe as he greeted Sheikh Mohammed and other rulers in the Emirates. Khalifa, the eldest son of the UAE’s first leader after the federation’s formation in 1971, held the most powerful position among the seven semi-autonomous city-states stretching along the shores of the Persian Gulf and the Gulf of Oman. His role as president derived from his standing as hereditary ruler of Abu Dhabi, the UAE’s largest and richest emirate. Abu Dhabi serves as home to the federal capital. Despite its size and vast oil wealth, Abu Dhabi often found itself overshadowed by the glitzy neighbouring emirate of Dubai, the Middle Eastern commercial hub that showcases the UAE’s bold visions and, at times, its debt-fuelled pipe dreams, including a massive palm-shaped artificial island, Palm Jebel Ali, that sits empty years after its creation. In 2009, as Dubai’s fortunes began to falter along with the global economy, Khalifa led efforts to protect the federation by pumping billions of dollars in emergency bailout funds into Dubai. The two emirates do not always see eye-to-eye on foreign policy decisions and compete commercially with one another. In 2003, he called for the creation of a new airline, Etihad Airways, which competes with Dubai’s successful and much larger carrier, Emirates Air. Khalifa increasingly used Abu Dhabi’s oil wealth to attract cultural and academic centres, such as branches of the Louvre museum and satellite campuses of New York University and the Sorbonne. He also presided over efforts to move the OPEC country beyond its reliance on petrodollars with investments in renewable energy research, including plans for a futuristic low-carbon desert city known as Masdar.