In late 2015 I had just arrived in London on sabbatical and was staying in a scruffy part of the city's north – full of cultural diversity and social disadvantage. On the first morning, as I emerged from my basement flat in search of the Sunday papers, a woman came towards me brandishing a greeting card and pen.

"Would you like to sign?" she asked. Just up the road was the strangely incongruous sight of a group of photographers pointing lenses at a modest '60s maisonette. "It's a congratulatory card," she explained, "from his neighbours to Jeremy. He's won."

Labour leader Jeremy Corbyn greeting supporters on the final week of the election campaign. Credit:Getty Images

And then it dawned on me. I was lodging just along from the newly elected leader of the British Labour Party: Jeremy Corbyn. I signed the card, explaining I was only a temporary neighbour, but was overjoyed at his victory.

Corbyn's rise is a most improbable political story. A complete outsider more at home marching with the comrades than debating in the Commons, he fought against apartheid, welfare cuts, privatisation and successive Gulf wars. He was on the progressive side of every major vote in his long parliamentary career.