Boris Johnson, the bombastic politician who played a decisive role in the 2016 Brexit referendum, is the new prime minister of the United Kingdom. He inherits the perplexing challenge of executing Britain's withdrawal from the European Union.
Johnson shook hands with Queen Elizabeth II at Buckingham Palace on Wednesday afternoon as he was granted royal assent to form a new government as the leader of the Conservative Party.
After his meeting with the Queen, Johnson was expected to give a speech to the nation outside the black door of Number 10, where, traditionally, new leaders lay out their mandate for the office.
Despite his Conservative Party's flimsy majority in Parliament, Johnson has pledged to do in three months what his predecessor Theresa May could not do in three years: lead Britain out of the EU.
He also inherits a mounting crisis with Iran, following the seizure of a British-flagged oil tanker last week, which has thrust the UK into the middle of a standoff between Tehran and Washington.
All of this falls in the lap of one of the most divisive politicians of his generation , who has said much on Brexit, Iran and many other topics, but has so far divulged little about any potential plan for his premiership.
"He's made a big pitch of re-energizing the country and bringing back optimism as a way he wants to do things," Tim Durrant, a senior researcher at the London-based Institute for Government think tank, told CNN. "We'll see if he has any details on the actual issues."
The governing Conservative party announced Tuesday that Johnson, a former mayor of London and British foreign secretary, won 66% of votes to become the party's next leader. The vote was triggered after an embattled May was forced into resigning after losing the support of her cabinet, many of whom were fed up with her inability to secure Brexit.
As prime minister, Johnson, 55, inherits the same problems of a deeply divided Parliament and nation, but under even more pressured circumstances.
"Even though Boris faces the same issues that May was confronted with when she took office ... the context of those issues is much different in terms of the parliamentary arithmetic and timing," Durrant said.
Throughout his leadership campaign, Johnson was vocal about his readiness to exit the EU without a deal, pledging to leave on October 31, the latest deadline for the UK to depart the bloc.
If he cannot negotiate a new deal with the EU, Johnson has said that he'd be willing to force Brexit through on that date. He has refused to rule out suspending parliament in order to do so.
Given that the EU says it isn't interested in reopening the Withdrawal Agreement -- the deal that May made with the bloc in 2018 but which has failed to satisfy both the Europhile and Euroskeptic wings of both the Tory party and Parliament -- there's seemingly no common position on which those negotiations could take place.
While Johnson's stance on Brexit has defined his leadership bid, his incendiary remarks on everything from religion to race have sparked criticism about his character, and his malleable political views have raised questions about his convictions. He notably broke ranks with then-prime minister David Cameron in 2016 to back Brexit at the last minute, making him the hero of the Brexiteers.
But Johnson's ability to shock, paired with his self-effacing humor and boyish charm, also helped him score two terms as London mayor, vaulted him into a stint as foreign secretary and ultimately made him a household name.
US President Donald Trump tweeted to congratulate Johnson on Tuesday: "He will be great!"
Johnson's father Stanley told CNN that he thinks his son will get along with Trump -- but warned that the relationship cannot be subservient: "We're going to have to be careful not to be too slavishly geared to America."
The man whose childhood dream was to be "World King" will see his tenure as prime minister defined by his ability to pull Britain out of the world's largest trade block. But even as the UK turns inwards, its significance in the global political landscape is seemingly at an inflection point.
First on Johnson's to-do list will be maneuvering an escalating crisis with Iran.
The British-flagged oil tanker, the Stena Impero, is still in Iranian custody days after it was captured by the Islamic Revolutionary Guard Corps in the strategic Strait of Hormuz. Since its seizure, questions have swirled over why more wasn't done by the UK government to protect British-flagged ships operating in the Strait -- which links the Gulf of Oman and the Persian Gulf -- despite warnings.
While calling for the tanker's release, Johnson will also need to tow the line with Washington. The tanker looks set to become a pawn in the mounting stalemate between Iran and Western powers, as Tehran fights to free itself from the crippling effects of US economic sanctions and reset nuclear talks.
The UK -- one of three European powers that have sought to save the 2015 Iran nuclear deal even after the US dropped out -- has worked to safeguard the landmark agreement while appeasing Washington, a balancing act that has become increasingly difficult as Iran raises the stakes in the Gulf.