How did an ex-banker end up leading Greece’s Syriza party?

The past decade has not exactly been short of surprises in Greek politics. But even to seasoned observers, the election of Stefanos Kasselakis as the new leader of Syriza, Greece’s main opposition party, stands out as one of the strangest developments yet.

A 35-year-old former Goldman Sachs trader with no prior political experience, Kasselakis has shattered conventional expectations by defeating his rival, Effie Achtsioglou – a party insider favoured by many senior officials – with a 56.69 per cent majority.

His victory comes as Syriza wrestles with internal divisions and existential questions. It is most likely because of this upheaval that Kasselakis – the most unlikely of left-wing candidates – was even able to challenge for the leadership of the party.

Living in Miami rather than Greece until earlier this year, Kasselakis is a political newbie who was virtually unknown to the Greek public until recently.