Despite the political partition of the island, Ireland competes at rugby internationally with an all-island team – and with a bespoke anthem that nobody loves but everyone tolerates. Ireland has become a leading rugby nation despite its tiny population and the fact that the sport is only the fourth most popular team game on the island by participation. Liam O'Callaghan's revelatory book shows that the rise of Irish rugby is inextricable from the tensions, debates and divisions – of politics, religion and class – that have defined modern Irish history.

In Blood and Thunder O'Callaghan traces the sequence of events that led Ireland's private Catholic secondary schools to embrace rugby – a game of the Anglo-Protestant elite – rather than soccer or Gaelic football: a choice that may have more to do with Ireland becoming a major rugby nation than any other factor. He tells the strange story of Irish rugby's various methods of dealing with the lack of an all-Ireland national anthem or flag. He shows how a game associated with elite enclaves came to capture the imagination of the general public, and how a game played and administered by Northern unionists and Southern nationalists survived the various political crises that could have torn it apart. He looks at the controversies and crises that have shaken Irish rugby – including the Northern Troubles, the IRFU’s long refusal to join the sporting boycott of apartheid South Africa, the Belfast rape trial, the rise and subsequent neglect of women’s rugby, and the rising toll of head injuries. And he traces the dramatic evolution whereby a rugby nation that was deeply attached to amateurism has made such a dramatic success of professionalism.

Blood and Thunder is more than a social and political history of Irish rugby. It is also a shadow-history of modern Ireland, rooted in brilliant original research and packed with terrific stories.