DUBAI, United Arab Emirates (AP) – Sheik Maktoum bin Rashid Al Maktoum, the emir of Dubai and one of the world’s foremost owners and breeders of thoroughbred horses, died Wednesday in Australia. He was 62.

Sheik Maktoum, also prime minister of the United Arab Emirates, was succeeded by his younger brother, Crown Prince Sheik Mohammed, the defense minister of the UAE, a federation of seven Gulf states.

Sheik Maktoum, visiting Australia for the prestigious Magic Millions yearling sales, died at the exclusive Palazzo Versace hotel on Australia’s Gold Coast, police said.

Authorities in Dubai would not give the cause of death. Australian police would say only that the emir did not die of suspicious causes. Australian media speculated he died of a heart attack.

and Al-Jazeera TV said he was believed to have a history of heart problems.

Sheik Maktoum owned hundreds of thoroughbreds and won some of the biggest races in the world.

Working with another brother, Sheik Hamdan, the Maktoum family put Dubai on the world racing map. The brothers founded Dubai- and British-based Godolphin Racing Inc., one of the world’s most successful stables, and created the Dubai World Cup, the world’s richest race with a $6 million purse.

“The Maktoums have such a passion for the sport, it’s unbelievable,” Kiaran McLaughin, who spent nine years training horses in Dubai for the family, said from his winter base in Florida. “It’s a great loss for our industry and for the whole world. He was a great man, a kind and bright man. It’s a very sad day.”

Sheik Maktoum owned Gainsborough Stud Management – with one farm in Kentucky, another in England and two in Ireland. Standing at stud at Gainsborough Stud at Newbury in southeast England are Elusive Quality and Quiet American, sires of Kentucky Derby winners Smarty Jones and Real Quiet.

“We would concur with others around the world that a visionary leader has been lost,” said D.G. Van Clief Jr., the commissioner of the National Thoroughbred Racing Association and president of Breeders’ Cup Ltd.

He said that “there has been no single family in recent years more influential in the conduct of the racing and breeding than the Maktoum family.”

Sheik Maktoum owned top flight horses such as Breeders’ Cup Turf winner Fantastic Light, English 2000 Guineas winner Shadeed and Irish Derby winner Shareef Dancer.

“Sheik Maktoum made a hugely significant contribution to the sport of horse racing and British thoroughbred racing and breeding in particular,” said Julian Richmond-Watson, senior steward of the Jockey Club in Britain.

The Godolphin stable has won nearly every major race outside the United States, but the Maktoums have said their biggest goal is to win the Kentucky Derby.

“He had over 200 horses in training and a lot of yearlings still to come in,” said Joe Mercer, the sheik’s longtime racing manager. He really enjoyed his racing. He knew what was going on and was a very good man to work for. He was a good loser and a good winner.”

Dubai declared 40 days of mourning, with government offices shutting down for seven days beginning Wednesday. The stock exchanges in Dubai and Abu Dhabi ceased trading, and many shops and businesses closed. In Dubai, the authorities said Sheik Maktoum’s funeral would be Thursday.

Dubai TV interrupted its programs to show a picture of the sheik smiling, as a Muslim cleric read verses of the Quran, Islam’s holy book.

“The United Arab Emirates today lost a historical leader who devoted his life to establishing the United Arab Emirates and enhancing its structure and the welfare of its people,” the government said.

Sheik Maktoum was born at home in Shindagha, near the mouth of Dubai Creek, and educated at a British university. He succeeded his father in 1990 as ruler of Dubai.

He tended to leave the day-to-day government of Dubai to his younger brother, but he took an active interest in foreign policy. He often represented the country abroad during the years when the former president, Sheik Zayed bin Sultan Al Nahyan, was ailing.

When Sheik Zayed died in 2004, Sheik Maktoum became acting president for a few hours until the new leader, Sheik Khalifa bin Zayed Al Nahyan, was proclaimed president.

“Sheik Maktoum’s death is a huge loss to Dubai but also to the world of horse racing. He was at the very center of everything Godolphin has achieved,” Godolphin racing manager Simon Crisford said.