Here's the story of UKIP's 'unfortunate' leadership contest
Now, Nigel Farage has admitted he is "technically" still the party's leader, and told Sky News that he would continue in the role until another leadership election takes place.
UKIP chairman Paul Oakden insisted to BBC Radio 4 that it was "an unfortunate situation," rather than a "farce."
Many would disagree.
James' resignation is the culmination a bizarre leadership contest, one of which was littered with gaffes, missed deadlines, and in-fighting.
Here is the timeline of UKIP's chaotic last few months:
Nigel Farage stepped down from the leadership after Britain voted to leave the EU, after "achieving his political ambition." He had resigned once before in 2015, only to "unresign" a few days later.
Steven Woolfe, a UKIP MEP, was widely touted to take Farage's place - until he missed the deadline for submitting his leadership ballot paper.
Diane James was subsequently elected, only to resign after 18 days. Her husband is seriously ill, and she was also shaken by a number of personal attacks in the days after her election.
UKIP's only elected MP weighed in:
James reportedly signed the leadership papers with her name followed by the words vi coactus, which means "under duress" in Latin.
It then emerged that UKIP had never sent those papers to the Electoral Commission, meaning that James had never actually been the leader.
There is no deputy leader as James failed to appoint one.
This means Farage is still the leader, but he says he has "done his bit" and has no interest in continuing.
Steven Woolfe is now the frontrunner to replace Farage - if he manages to submit his leadership ballot on time.