Image copyright AFP / Getty Images Rex Tillerson, nominated by US President-elect Donald Trump to be secretary of state, runs the world's most valuable, publicly traded oil company.
The 64-year-old, Texas-born head of Exxon Mobil has worked for the company in the US, Yemen and Russia, and is known for his close ties with Russian President Vladimir Putin.
But Mr Tillerson's links to the Kremlin, which awarded him the Order of Friendship in 2013, and his lack of experience have drawn criticism from both Democrats and Republicans, setting up a potential battle in his confirmation hearings in the Senate early next year.
The Texas oil chief is likely to come under intense scrutiny for the potential benefits Exxon might receive in US foreign policy he would preside over at the State Department.
While critics raise concern about his ability to trade in his corporate interest for a national one, some supporters suggest his background as a global dealmaker may bring fresh perspective to the nation's top diplomatic post.
Mr Trump's transitional team said Mr Tillerson would "help reverse years of misguided foreign policies and actions __that have weakened" the country's global standing.
The Texan said he shared Mr Trump's vision "for restoring the credibility of the United States' foreign relations and advancing our country's national security".
In Putin's pocket?
Mr Tillerson's nomination follows revelations __that US intelligence agencies believe Russia acted covertly to help Mr Trump defeat Hillary Clinton in the election, leaving some critics unnerved by his close relations with Moscow.
During his time at Exxon, Mr Tillerson has forged multibillion-dollar deals with Russia's state oil company, Rosneft, including an agreement to explore underground resources in Siberia that could be worth billions of dollars.
He is also known to be a friend of Igor Sechin, Rosneft's executive chairman who was formerly Mr Putin's deputy prime minister. Mr Sechin has been called Russia's second most powerful man.
Mr Tillerson has publicly spoken out against international sanctions placed on Russia over its annexation of Crimea.
In 2014, Exxon filed a report saying the US government and European Union's sanctions cost the company a maximum of $1bn (£790m) in damage to joint ventures.
Republican Florida Senator Marco Rubio expressed "serious concerns" about Mr Tillerson's nomination, noting that the post needed to go to "someone who views the world with moral clarity, is free of potential conflicts of interest, has a clear sense of America's interests, and will be a forceful advocate for America's foreign policy goals to the president, within the administration, and on the world stage".
Republican Senator John McCain of Arizona also voiced his scepticism, asking "what kinds of business we do with a butcher, a murderer, a thug, which is exactly what Vladimir Putin is".
But Mr Tillerson is also known to be a supporter of free trade, a departure from the anti-trade views held by Mr Trump, who has decried the existing US agreements as a hindrance to the American economy.
Political outsider
Mr Tillerson has spent his entire career, more than 40 years, working for Exxon. He joined the company as a production engineer, fresh from University of Texas, Austin, and worked his way up to take the top job in 2006.
He had been expected to retire next year.
The lifelong Exxon employee beat a long list of seasoned candidates in the running for the post, including former Massachusetts Governor Mitt Romney; Senator Bob Corker, the chairman of the Senate Foreign Relations Committee; and former CIA chief David Petraeus.
To counter concerns over his lack of experience, former Secretary of Defence Robert Gates hailed Mr Tillerson as "a global champion of the best values of our country" while former Secretary of State Condoleezza Rice shared similar sentiment.
But as Mr Gates noted, Exxon is a client of his and Ms Rice's consultancy firm RiceHadleyGates.
Though Mr Tillerson appears to fit with Mr Trump's right-wing cabinet, he has stirred controversy among some social conservatives who condemn his more liberal policies.
As president of the Boy Scouts of America from 2010-2012, Mr Tillerson was part of the push to allow gay scouts and leaders into the organisation, although a ban on openly gay adult scout leaders remained in place until 2015.
Evangelical leader Tony Perkins, the president of the Family Research Council, slammed Mr Tillerson's nomination, noting Exxon's history of donating to family-planning organisation Planned Parenthood.
Mr Tillerson is also a former director of the United Negro College Fund, a US organisation that funds scholarships for black students and supports historically black colleges and universities.
Fossil fuel advocate
Exxon, which has about 75,000 employees around the world, has been accused of trying to cover up the risks of climate change and lying to the public.
The company has dealt with a series of state investigations into how much it knew about climate science, leaving many environmental activists concerned about his nomination.
"He and other company executives led Exxon Mobil in funding outside groups to create an illusion of scientific uncertainty around the overwhelming scientific consensus on climate change," said Neera Tanden, the president of the Center for American Progress and a Clinton ally.
Yet Mr Tillerson accepts climate change is real and has spoken of "catastrophic" consequences if it were left unchecked.
"For many years, Exxon Mobil has held the view that the risks of climate change are serious and do warrant action. We believe that addressing the risk of climate change is a global issue," he said last May.
Though he is so far the only member of Trump's candidate to acknowledge the existence of climate change, Mr Tillerson remains committed to the continued use of fossil fuels.
"The reality is there is no alternative energy source known on the planet or available to us today to replace the pervasiveness of fossil fuels in our global economy, in our very quality of life, and I would go beyond that and say our very survival," he said.
He is, however, open to the idea of a carbon tax to reduce emissions, a view likely to clash with those held by new colleagues in government.