The ruler of the Gulf Arab emirate of Dubai, Sheikh Maktoum bin Rashid al-Maktoum, has died during a private visit to Australia. The exact cause of his death is unclear, but the well-known international racehorse owner and breeder had been suffering heart problems. Maktoum, who was in his mid 60s, was also vice president and prime minister of the seven member United Arab EmiratesThe UAE is a federation of seven emirates which include Dubai and are located on the coast of the Gulf and the Gulf of Oman. It is unknown exactly how many wives and children he had. Domestically, Maktoum maintained a low profile, preferring to allow his younger brothers to run the day-to-day affairs of Dubai, the region’s trade and tourism hub. But internationally he was best known as co-owner of Dubai’s Godolphin stables which competes in major horse races. He also spent several weeks a year in Britain. The UAE declared 40 days of mourning and state institutions will close for a week. His brother, Sheikh Mohammed, is expected to take over. Many analysts say he has been the real driving force behind Dubai’s efforts to wean itself off dwindling oil reserves and become a luxurious spot for shopping and tourism.