Jeremy Corbyn is likely to remain an important figure in Labour Party politics, even after his tenure as its leader. Partly because as a backbencher, he is still able to inform debates not just within the Labour Party but in British politics more broadly. He still attracts (virtual and live) audiences and media attention, for good or ill, not least as the ex-party leader, but also as a controversial figure within the labour movement. Moreover, Corbyn's time in office exposed the schisms within the party, provoking a debate at the heart of social democracy over its future and relevance in the twenty-first century. This volume presents a timely collection of essays on a range of issues relevant to understanding Corbyn as a politician and as a leader and Corbynism as a project and as a progressive alternative.

Following a damaging defeat in the general election under Ed Miliband, Labour's search for a new leader culminated in the surprise election of Jeremy Corbyn after an energetic, lively and optimistic leadership campaign in 2015. During the leadership election he:

This was a thoroughly left-leaning agenda, which chimed with some audiences across the country as authentic. At the start of the campaign, few expected Corbyn to win; by the end, many were surprised, especially those Labour MPs who had nominated Corbyn simply to expand the debate within the leadership election (Denham, Roe-Crines & Dorey 2020). As leader, he would have to defend his position from continual critique from his own backbenchers, including a formal leadership challenge by Owen Smith in 2016.