Sheikh Hamdan bin Rashid Al Maktoum, deputy ruler of Dubai and the finance minister of the United Arab Emirates (UAE), has died, his brother said on Wednesday. He was 75.

Sheikh Hamdan served as deputy leader of Dubai under his brother, Sheikh Mohammed bin Rashid Al Maktoum, the hereditary ruler of the city-state who also serves as prime minister and vice president of the UAE.

Emirati officials announced his death without specifying the cause. Sheikh Hamdan had been in poor health for several months.

Last fall, he flew abroad for an unspecified surgery and in recent weeks his brother Sheikh Mohammed tweeted prayers for his recovery.

Born December 25, 1949, the second son of late ruler Sheikh Rashid Bin Saeed Al Maktoum, he grew up in what was known as the Trucial States, a collection of Arab sheikhdoms along the southern shore of the Persian Gulf that was part of a British protectorate since 1820.

When the UAE formed its first Cabinet in 1971, Sheikh Hamdan became finance minister and held the post until his death, attracting foreign investment, managing the country's oil wealth and, along with his brother, overseeing the transformation of Dubai into a regional financial hub.

The country separately has a minister of state for financial affairs. He led Emirati delegations to the International Monetary Fund and the Organization of the Petroleum Exporting Countries (OPEC) Fund for international development.

Sheikh Hamdan controlled a wide array of conglomerates reaching across Dubai’s economy, such as the Dubai Ports Authority, Dubai World Trade Center and Dubai Natural Gas Company Limited.

Like his brother, he became a big name in horse racing out of the UAE, founding Shadwell Racing in 1981, an operation with a legacy of producing star thoroughbreds. His funeral service will be restricted to family because of COVID-19, according to Dubai's government-run media office, which ordered government offices closed for three days of mourning.

"Today we lost one of the most loyal men of the UAE after a life full of giving and sincere patriotism,” wrote the country's de facto ruler, Abu Dhabi Crown Prince Mohammed bin Zayed Al Nahyan.