Boris Johnson -The UK’s next prime minister.

UNITED KINGDOM Often abbreviated to just "UK," the United Kingdom is a shortened form of the country's full name, which is the United Kingdom of Great Britain and Northern Ireland. The state itself consists of four component countries—England, Scotland, Wales, and Northern Ireland—and if you're referring to all four as a single body, you should always use the phrase "United Kingdom" to describe them. Although England is the largest of the UK's four states, and the one in which the UK's government traditionally meets, it is nonetheless only a component of the UK, and shouldn't be used to describe the entire country. Visiting Edinburgh, for example, is not visiting England, just as visiting Trenton is not visiting Massachusetts.

The 55-year-old Conservative member of Parliament, former foreign minister, and former mayor of London won the Conservative leadership contest on Tuesday. He will replace outgoing Prime Minister Theresa May, who was forced to step aside after failing to deliver a Brexit deal.

An ardent backer of Brexit and vocal opponent of May’s deal, Johnson has a reputation for brashness, bending the truth, and bad hair, which has earned him comparisons to President Donald Trump (who is a fan of his).

Johnson can be cringeworthy, but that’s also somehow part of his charm — and why he’s among the most popular Conservative politicians in an unpopular party.

His critics see him as a calculating self-aggrandizer who’d do or say anything to get ahead. He’s also generated considerable controversy over racist, sexist, and Islamophobic statements he’s made.

Boris Johnson, editor of the Spectator magazine at the time, sits in his London office reading the anniversary issue of the magazine to mark 175 years of publication, on September 25, 2003. Jim Watson/AFP/Getty Images

Johnson, whose full name is Alexander Boris de Pfeffel Johnson, was born in New York City (he gave up his US citizenship in 2016) and was educated at the prestigious English prep school Eton, and later at Oxford University.

He began his career as a journalist, where he was known for playing loose with facts and writing skeptically about the European Union as a Brussels correspondent. He became a member of Parliament in 2001, and in 2008, he mounted a successful bid to become the mayor of London.

GREAT BRITAIN Great Britain is the name of the largest island in the British Isles and is also a political entity consisting of three countries: England, Scotland, and Wales. It is sometimes used interchangeably with the term "United Kingdom," but to prevent confusion—and to avoid possible offense to those from Northern Ireland—it's best if you don't do this. As the UK's full name suggests, Northern Ireland is not part of Great Britain, hence "United Kingdom of Great Britain and Northern Ireland." To add even more to the confusion, there are some islands that are part of these countries (like England’s Isle of Wight and Scotland’s Isle of Skye) that, although not on the physical island of Great Britain itself, are often included because they’re part of countries that are predominantly on Great Britain. So political Great Britain is slightly larger than geographic Great Britain. But if you get this wrong, you can at least take comfort in knowing you're not the only one to do so. Even the UK's official Olympic team styles itself as "Team GB," despite including athletes from Northern Ireland.

Johnson’s record as mayor was mixed; he was a booster for London and loved publicity stunts. He presided over the 2012 London Olympics, where, as the Guardian put it, he demonstrated “his greatest strength as mayor — an ability to generate laughter and a mood of upbeat bonhomie,” mostly because of the infamous zipline incident.

Johnson served two terms as mayor, declining to run again in 2016, just as the Brexit referendum was getting underway.

Boris Johnson boards the Vote Leave Brexit Battle Bus on May 17, 2016, in Stafford, England. Johnson and the Vote Leave campaign toured the UK in the bus hoping to persuade voters to back leaving the European Union in the referendum that June.

Johnson broke with his political allies, including the pro-Remain Conservative Prime Minister David Cameron, to become the unofficial leader of the “Vote Leave” campaign. During the campaign, he made a lot of questionable assertions — including a disputed claim that the UK was sending £350 million a week to the EU, which he said could instead help fund Britain’s popular National Health Service.

 

Johnson served two terms as mayor, declining to run again in 2016, just as the Brexit referendum was getting underway.

Boris Johnson boards the Vote Leave Brexit Battle Bus on May 17, 2016, in Stafford, England. Johnson and the Vote Leave campaign toured the UK in the bus hoping to persuade voters to back leaving the European Union in the referendum that June.

Johnson broke with his political allies, including the pro-Remain Conservative Prime Minister David Cameron, to become the unofficial leader of the “Vote Leave” campaign. During the campaign, he made a lot of questionable assertions — including a disputed claim that the UK was sending £350 million a week to the EU, which he said could instead help fund Britain’s popular National Health Service.

He also argued that the EU’s freedom of movement made the UK less safe and that Brexit would allow the UK to regain control over its borders.

The Leave campaign won the referendum on June 23, 2016. Cameron resigned, and Johnson was seen as his obvious successor. But Johnson’s candidacy imploded after a political ally betrayed him.

Instead, Theresa May became prime minister. Johnson had to settle for the job of foreign secretary — a post he quit in July 2018 in protest of May’s handling of Brexit.

Johnson continued to frustrate May’s Brexit efforts from the sidelines, along with fellow Brexiteers in Parliament. Those defeats ultimately forced May to resign. And Johnson got another chance to be prime minister.

BRITAIN Here's where things get really confusing: Although commonly used as a colloquial shorthand for the UK, Britain is also a political entity that doesn't really exist anymore. We've established that Great Britain is the name of the island containing England, Scotland, and Wales, but "Britain" is really an archaic term for the Roman territory of Britannia, also called Britannia Major to distinguish it from Britannia Minor (the area of France now called Brittany). Scotland was never conquered by the Romans, so Britain—if you're being pedantic—refers only to England and Wales. It's probably best to assume anyone who says "Britain" is just shortening "Great Britain" for convenience—unless you're actually in second-century Britain, in which case you probably have bigger problems.

Johnson promised Conservative MPs and party voters that he would deliver Brexit by the October 31 deadline no matter what — by pushing for a new deal and stepping up preparations to leave the EU without a deal if necessary.

The pitch worked. Johnson easily defeated Foreign Minister Jeremy Hunt to become the next party leader and future prime minister.

Johnson will now face the same Brexit impasse as his predecessor. May’s Brexit deal remains unpopular, and the EU has insisted it won’t renegotiate it; Parliament has continued to reject a no-deal Brexit. Johnson has about 100 days to deliver on his Brexit promise. The question is: can he?