The resignation of Zia Yusuf as Reform UK's chairman matters because he was a central character in the stand out trend in British politics since the general election – the rise and rise of Nigel Farage's party.
After 11 months in the role, Yusuf said on Thursday that working to get the party elected was no longer "a good use of my time", without expanding further.
Farage described Yusuf as a huge factor in Reform's success in last month's elections, but added that he believed he had "had enough" of politics.
It comes after Yusuf said it was "dumb" for Reform's newest MP to call for a ban for the burka - a veil worn by some Muslim women that covers the face and body.
I first met this thirty-something Muslim son of Sri Lankan immigrants, a former Conservative, when he was unveiled by Reform almost exactly a year ago, as a donor who had just handed the party £200,000.
Yusuf is a self-made multi-millionaire after setting up and then selling Velocity Black, a luxury concierge service.
Not long after his donation to Reform, he was offered and accepted the job of party chairman. And he wouldn't just be someone behind the scenes, he would be a public figure too.
So how can we measure how important this moment is?