Theresa May will leave office on Wednesday after going to Buckingham Palace to see Queen Elizabeth, who will formally appoint Johnson before he enters Downing Street.
Former London mayor Boris Johnson on Tuesday won the race to become Britain's next prime minister, defeating Foreign Secretary Jeremy Hunt in the Conservative Party leadership contest.
Johnson defeated Hunt by 92,153 votes to 46,656 votes cast by members of the Conservative party. He will officially replace outgoing Prime Minister Theresa May on Wednesday.
Boris Johnson in dates
Here are key dates in the life of Boris Johnson, who was named the new Conservative leader Tuesday and will become Britain's next prime minister.
- June 19, 1964: He is born as Alexander Boris de Pfeffel Johnson in New York, where his father is studying at Colombia University.
- 1983: Having been schooled at Eton, he enters Oxford's Balliol College where he graduates in classics four years later.
- 1987-1988: Works as a journalist for The Times newspaper, from where he is sacked for fabricating quotes.
- 1989-1994: Becomes The Daily Telegraph's EU correspondent in Brussels, known for his deeply eurosceptic writings.
- 1999-2005: Editor of news magazine The Spectator.
- 2001: Elected as Conservative member of parliament for the Henley constituency near London. Re-elected in 2005.
- 2008: Defeats Ken Livingstone to become mayor of London. After being re-elected for another four years in 2012, he oversees the city's hosting of that year's Olympic Games.
- 2015: Elected as MP for Uxbridge and South Ruislip constituency on the outskirts of London. Re-elected in 2017.
- June 2016: Prime minister David Cameron resigns when Britons vote to leave the European Union. Johnson -- a Brexit champion -- pulls out of the race to replace him at the last minute after a key ally betrays him.
- July 13, 2016: He is appointed foreign secretary in the government of the new prime minister, Theresa May.
- July 9, 2018: Resigns over May's Brexit strategy.
- July 23, 2019: Wins the race to replace May as Britain's next prime minister, beating Foreign Secretary Jeremy Hunt in the Conservative leadership contest.
- July 24, 2019: Due to be formally installed as prime minister at a meeting with Queen Elizabeth II.