Prime ministers are judged on their policies, the legacy they leave behind, and of course, their ability to win elections. Tony Blair and Margaret Thatcher were both controversial figures, but they each managed to win three large majorities.
Theresa May has contested one election and come up short.
In fact, she hasn't even reached one year in her tenure as PM after she replaced David Cameron in the wake of the EU referendum in July 2016.
But things can quickly change in politics, especially after an election. May's future remains in doubt.
There is a high chance she won't last more than a few days or weeks, which means her tenure at Number 10 will be among the shortest ever.
Out of 54 British prime ministers, May is currently the 48th longest serving leader on 300 days, ahead of the Earl of Bute and behind Sir Alec Douglas-Home.
This compares to more recent PMs including Thatcher at number seven, Blair at number nine and David Cameron at 22.
But May could end up as the shortest serving PM for a century since fellow Conservative Bonar Law, who lasted 211 days between 1922 and 1923.
Her party may have won the most seats, but May faces a tough challenge to extend her tenure at the top.