United Arab Emirates President Sheikh Khalifa Bin Zayed Al Nahyan has died at the age of 73, state news agency WAM reported on Friday. He was also ruler of the Abu Dhabi emirate and supreme commander of the UAE Armed Forces. The UAE Ministry of Presidential Affairs announced that the nation will observe a 40-day state mourning with the flag flown at half-mast starting Friday, and suspend work at all ministries, departments, as well as federal, local and private entities for three days. The ministry mourned the people of the UAE, the Arab and Muslim nations and the whole world on the death of the leader of the nation. Under the nation’s constitution, Vice President and Prime Minister of UAE and Ruler of Dubai Sheikh Mohammed Bin Rashid Al-Maktoum will act as interim president until the Federal Council, which groups the rulers of the seven emirates, meets within 30 days to elect a new president. Sheikh Khalifa was appointed as the second president of the UAE in 2004, succeeding his father and founder of the nation, Sheikh Zayed Bin Sultan Al-Nahyan. Sheikh Khalifa is expected to be succeeded as ruler of Abu Dhabi by his half-brother Crown Prince Sheikh Mohammed Bin Zayed Al-Nahyan. Sheikh Khalifa succeeded to the posts of ruler of Abu Dhabi and president of the UAE on 3 November 2004, replacing his father Sheikh Zayed, who had died the day before. In 2009, Sheikh Khalifa was re-elected as president of UAE for a second five-year term. Sheikh Khalifa’s role had been largely ceremonial since he suffered a stroke and underwent surgery in 2014. Since then, Sheikh Mohammed Bin Zayed has been widely seen as the de-facto leader of the UAE, handling day-to-day affairs for the nation. Sheikh Khalifa is married to Shamsa Bint Suhail Al-Mazrouei and has eight children.