Manchester, 2018: Pep Guardiola and Jose Mourinho lead their teams out to face each other in the 175th Manchester derby. They are first and second in the Premier League, but today only one man can come out on top. It is merely the latest instalment in a rivalry that has contested titles, traded insults and crossed a continent, but which can be traced back to a friendship that began almost 25 years ago.

Barcelona, late-nineties: Johan Cruyff’s Dream Team is disintegrating and the revolutionary manager has departed, but what will come next will transform the future of football. Cruyff’s style has changed the game, and given birth to a generation of thinkers: men like Ronald Koeman, Luis Enrique, Laurent Blanc, Frank de Boer, Louis van Gaal, and Cruyff’s club captain Pep Guardiola and a young translator, Jose Mourinho.

The Barcelona Legacy is a book in part about tactics, about how the theories that underpin the modern game were forged by Cruyff and his successors, but also about the people and personalities who gathered at the Camp Nou for what was effectively the greatest coaching seminar in history, about their friendships and rivalries and, in one case, an apocalyptic falling out that continues to shape the game today.