As deputy commander of the armed forces, he had sway over multibillion dollar arms purchases and direct dealing with defense officials from the U.S. and other Western allies. His senior role with the Qatar Investment Authority gave him a powerful voice over the direction of one of the world's most active sovereign wealth funds, whose landmark stakes around the world include Harrods department store in London and luxury jeweler Tiffany & Co.
But Sheik Tamim's most enduring international image to this point has been linked to sports.
His crowning moment came as he helped win Qatar's bid to host the 2022 World Cup. Sheik Tamim and other Qatari officials, however, later faced complaints that the nation used its vast wealth to swing support its way from football federation members in Africa and elsewhere.
Last year was less positive an International Olympic Committee member since 2002, Sheik Tamim headed Doha's unsuccessful bid for the 2020 Olympics. Qatar's capital has been mentioned as a possible bidder for the 2024 Games an effort that could get a boost from the new emir.
Sheik Tamim who also has served as head of Qatar's Olympic panel since 2000 helped avoid an embarrassing showdown with Olympic overseers by organizing the first female athletes representing Qatar for last year's London Olympics. Neighboring Saudi Arabia and the Asian country of Brunei also sent their first women Olympic athletes.
Sheik Tamim's Qatar Sports Investments owns 70 percent of the football club Paris Saint-Germain.
Sheik Tamim was educated at schools in England and then graduated from Sandhurst, Britain's prestigious military academy and alma mater for many Middle Eastern leaders.
His two wives include Sheika Anoud bint Mana al-Hajri, a member of a prominent Qatari family. He has six children.