Republican National Committee (RNC) chairman Reince Priebus, 44, was hailed as a "superstar" in US President-elect Donald Trump's victory speech, so few were surprised when he was selected as Chief of Staff - traditionally the first post that gets filled after election day.
In charge of day-to-day operations at the White House, he will remain one of the top and most trusted advisers to Mr Trump.
As chairman of the RNC, Mr Priebus provided Mr Trump's bare- bones campaign with the support it needed to reach voters across the country. He also stuck by the candidate through the ups and downs of the presidential campaign while other Republicans refused to endorse him or distanced themselves when scandals such as Mr Trump's lewd comments about women in a 2005 tape erupted.
Born in New Jersey and raised in Kenosha, Wisconsin, Mr Priebus has access to a wide spectrum of Republican lawmakers and can help Mr Trump push through legislative change.
He is also a close friend of House Speaker Paul Ryan - a relationship that could help oil the wheels between the executive and legislative branches of government.
While he has never held elected office, Mr Priebus is still regarded as a political insider.
In 2007, he became chairman of the Wisconsin Republican Party and in 2010 played a key role in the election of Mr Scott Walker as the state's governor.
Mr Priebus, a lawyer, became the RNC chairman in 2011, after serving as its general counsel. He is often praised for his humility and work ethic.
He is also known for leading the "autopsy" report which called for the Republican Party to be more inclusive after its candidate Mitt Romney lost the presidential race to Mr Barack Obama in 2012.
On his new appointment, Mr Priebus said in a statement that he was "grateful to the President- elect for this opportunity to serve him and this nation as we work to create an economy that works for everyone, secure our borders, repeal and replace Obamacare and destroy radical Islamic terrorism".
While his new post is traditionally the top job in the White House, Mr Trump's transition team has said that Mr Priebus will work with Mr Steve Bannon, appointed chief White House strategist, as "equal partners to transform the federal government". Pundits are watching closely how this joint leadership will pan out.