DOHA - The emir of gas-rich Qatar, a major actor on the world diplomatic stage and key backer of Arab Spring uprisings, on Tuesday stepped down in favour of his 33-year-old son Sheikh Tamim.

Sheikh Hamad bin Khalifa al-Thani’s abdication after 18 years on the throne marks a first in the Arab world although analysts do not expect significant changes in the way the super-rich Gulf state is ruled.

“I address you today to announce that I am handing the rule over to Sheikh Tamim bin Hamad al-Thani,” the 61-year-old emir told Qataris in a televised speech.

The decision marks the beginning of “a new era in which a young leadership will hold the banner that would place the hopes of the coming generation upon its priorities,” he added. Sheikh Hamad suffers from kidney problems but officials insist his motivation for stepping down was not health-related but rather a determination to bring a younger leadership to the fore.

The emir appeared to be in good health while delivering his speech on Tuesday and also during his weekend meetings with US Secretary of State John Kerry and French President Francois Hollande. After the speech, Al-Jazeera television aired footage of citizens arriving at the palace in Doha to swear allegiance to a tall, smiling Tamim, who stood next to his father to welcome the visitors.

Among those who arrived to congratulate the father and son was influential Muslim cleric Sheikh Yusuf al-Qaradawi, who embraced both.  Qaradawi is a controversial figure in the West and has millions of supporters, mostly from the Muslim Brotherhood - which Qatar reportedly supports. Sheikh Hamad, who used Qatar’s immense gas wealth to drive its modernisation, came to power in a coup in which he overthrew his own father Sheikh Khalifa in June 1995.

His decision to abdicate sees Tamim propelled into the youngest sovereign of any of the Gulf Arab monarchies. The occasion was marked by the declaration of Tuesday as a public holiday. “Such a generational shift will make waves in the region, even though the Qataris informed other countries of their decision,” said Doha-based analyst Salman Shaikh. “This decision is consistent with Qatar’s policy,” he told AFP. “They have been preparing for change for some time, they want to move to the younger generation.”

Hamad hands over to his son a Gulf state that under his rule has developed into a political and economic powerhouse with multi-billion-dollar investments across the world.

According to the World Bank, Qatar recorded a gross domestic product (GDP) of $173 billion in 2011, while average per capita income in 2012 stood at 98,000 euros ($128,811).

Saudi Arabia, whose 90-year-old monarch is frequently hospitalised, was quick to congratulate Tamim, while the United Arab Emirates voiced hope of stronger ties between the two Gulf states.

A diplomatic source said that Tamim, whose country is an ally of the United States, enjoys “excellent relations with the West, notably with the US and France”.

Tamim, born in 1980, is the second son of the emir and his second wife Sheikha Mozah and has been groomed for years to take the helm of the super-rich Western ally.

Diplomats said that over the past three years the emir has increasingly transferred military and security responsibilities to Tamim, who like his father went to the British military academy Sandhurst.

The tiny Gulf peninsula holds the world’s third largest gas reserves and produces roughly 77 million tonnes of liquefied natural gas per year, making it the world’s largest supplier.

Under Sheikh Hamad, Qatar played a role in Middle East affairs massively out of proportion to its size, becoming a major backer of the Arab Spring uprisings in both Libya and Syria.

Also under Hamad’s rule, the Qatar Investment Authority, the emirate’s sovereign wealth fund, invested billions of dollars in businesses ranging from Germany’s Volkswagen to French energy giant Total and Britain’s Sainsbury’s supermarket chain and Barclays Bank.

The Gulf state also developed a powerful media empire through Al-Jazeera, the first pan-Arab satellite channel which also broadcasts in English, and is preparing the launch of Al-Jazeera America.

And Qatar put itself on the world sporting map with a successful bid to host the 2022 FIFA World Cup.

The transfer of power is expected to be accompanied by a major cabinet reshuffle which would see the departure of powerful Prime Minister Sheikh Hamad bin Jassem bin Jabr al-Thani, who has held the post since 2007.