In 1845, European potato fields from Spain to Scandinavia were attacked by a novel pathogen. But it was only in Ireland, then part of the United Kingdom, that the blight's devastation reached apocalyptic levels, leaving more than a million people dead and forcing millions more to emigrate.

In Rot, historian Padraic X. Scanlan offers the definitive account of the Great Famine, showing how Ireland's place in the United Kingdom and the British Empire made it uniquely vulnerable to starvation. Ireland's overreliance on the potato was a desperate adaptation to an unstable and unequal marketplace created by British colonialism. The empire's laissez-faire economic policies saw Ireland exporting livestock and grain even as its people starved. When famine struck, relief efforts were premised on the idea that only free markets and wage labor could save the Irish. Ireland's wretchedness, before and during the Great Famine, was often blamed on Irish backwardness, but in fact, it resulted from the British Empire's embrace of modern capitalism.

Uncovering the disaster's roots in Britain's deep imperial faith in markets, commerce, and capitalism, Rot reshapes our understanding of the Great Famine and its tragic legacy.