Her gamble yielded results that were nothing short of disastrous for the party.
What is the Democratic Unionist Party?
While May expressed plans to stay in power and create a minority government with the Democratic Unionist Party of Northern Ireland, her unexpected defeat leaves many Britons wondering what's next for the country. The DUP said only that it would enter talks.
Corbyn: "The prime minister called the election because she wanted a mandate". "We don't know when Brexit talks start", tweeted European Council President Donald Tusk on Friday as the election results became clear.
Voters may have been unimpressed with her refrain that "no deal is better than a bad deal" because it raised the prospect of Britain crashing out of the EU without a trade-and-immigration system to replace the existing, well-integrated procedures that have evolved over decades of European integration.
The Tories only managed to win 318 seats - eight shy of an overall majority - and now reply on the DUP to prop them up and pass laws.
But Mrs May, facing scorn for running a lacklustre campaign, was determined to hang on.
"Other personnel issues are for other days", she said.
The news came as May prepared to name the rest of her cabinet, after revealing on Friday that her five most senior ministers would remain in their posts.
I think, you know, we see this election extremely effective Labour Party campaign, which has not allowed the Labour Party to win the election outright but has enabled it to deny the conservatives and Prime Minister May a parliamentary majority.
She will clearly be looking to get as much out of the prime minister as possible in exchange for support.
SIMON: This election, of course, was called to try to cement the Conservative Party majority and the mandate for what we call Brexit. "I would have thought that's enough to go, actually, and make way for a government that will be truly representative of all of the people of this country".
And the EU's Budget Commissioner Gunther Oettinger said: "We need a Government that can act. Let's put our minds together on striking a deal", he said on Twitter. The opposite has happened, she has been dealt a weak hand, having lost the majority in the parliament.
Labour also showed signs of recovering from its nadir in Scotland, picking up six seats from the SNP. "Just look across the channel at Britain".
In Brussels, home of the European Union, there was a mix of puzzlement, confusion and frustration over the chaos of British politics.
"The irony of this is that Theresa May is calling this a certainty government and talking about how it's delivering certainty", said Brian Klaas, a fellow in comparative politics at the London School of Economics. "Whoever it is, they are going to have to make deals with other political parties, and nearly every other political party that has an MP in the new parliament wants a softer version of Brexit", says French.
"I'm afraid we ran a pretty terrible campaign", Ms Soubry said.
Many voters seemed to think there was no point voting for the UKIP because the party had already achieved its main goal of winning the 2016 referendum on leaving the European Union.
The British PM was forced to relinquish her two closest aides - joint chiefs of staff Nick Timothy and Fiona Hill - as she struggled to reassert her authority.
Senior Labour figures who had been touted as potential successors, including Chuka Umunna and Hilary Benn, praised Mr Corbyn's performance during the campaign.
A survey of 14,000 people after they had voted by former Conservative donor Lord Ashcroft found that two-thirds of 18- to 24-year-olds cast their ballots for Mr Corbyn's party.