With a taste for elections, the businesswoman and healthcare consultant stood as an MEP for South East England and won, joining Nigel Farage in the European Parliament.
She then quietly carved her way through the party hierarchy becoming its deputy chairwoman and spokeswoman on justice and home affairs.
She briefly blipped on the radar after telling LBC's Iain Dale that she admired Vladimir Putin as a "strong leader" and suggested UKIP and the Russian leader shared a common distaste of the European Union.
When she announced her candidacy following Mr Farage's election, she was catapulted to front runner after the deputy leader Paul Nuttall refused to join the race and second favourite Steven Woolfe was disqualified.
This made Ms James an unlikely favourite, winning the support of Mr Farage and the party's moneybags, Arron Banks, who helped fund her campaign.
Sky News understands that on his advice, she pulled out of the 12 leadership hustings to the consternation of many in the party and decided instead to run her own events, unchallenged by debate.
Her election spells trouble for the anti-Farage modernists including former deputy chairwoman Suzanne Evans, UKIP's only MP Douglas Carswell and fellow MEP Patrick O'Flynn.
In an interview this summer she made it clear she supports a purge: "There's going to be no place in UKIP under my leadership for those who have sought or seek to destabilise, destroy or even obstruct what a new constitution will outline for the new governance of this party."
But with defections and disunity rife, and a sense that the party has achieved its mission, will she be able to maintain the momentum set by her predecessor?
http://news.sky.com/story/the-full-s...eader-10580026