The people of Ireland did not benefit from the political competition in Britain. In the mid-1800s, Ireland was an agricultural nation, and the great majority of the rural population (outside of the northern counties of Ulster, which were partly Presbyterian) were Irish Catholics. They typically rented their land from a tiny minority of Church of England Protestant landowners, who often resided in England. Trapped in an exploitative tenant system driven by a pernicious combination of religion and class, Irish peasants lived in abominable conditions. Wretched one-room mud cabins dotted the Irish countryside; the typical tenant farmer could afford neither shoes nor stockings.

Despite the terrible conditions, population growth sped upward, part of Europe’s general growth trend begun in the early eighteenth century (see Chapter 17). Between 1780 and 1840, the Irish population doubled from 4 million to 8 million. Extensive cultivation of the humble potato was largely responsible for this rapid growth. A single acre of land planted with the nutritious potato could feed a family of six for a year, and the hardy tuber thrived on Ireland’s boggy wastelands. About one-half of the Irish population subsisted on potatoes and little else.

As population and potato dependency grew, however, conditions became more precarious. From 1820 onward, deficiencies and diseases in the potato crop occurred with disturbing frequency. Then in 1845 and 1846, and again in 1848 and 1851, the potato crop failed in Ireland. Blight attacked the young plants, and leaves and tubers rotted. Unmitigated disaster — the Great Famine — followed, as already impoverished peasants experienced widespread sickness and starvation.

The British government, committed to rigid free-trade ideology, reacted slowly. Relief efforts were tragically inadequate. Moreover, the government continued to collect taxes, landlords demanded their rents, and tenants who could not pay were evicted and their homes destroyed.

The Great Famine shattered the pattern of Irish population growth. Fully 1 million emigrants fled the famine between 1845 and 1851, mostly to the United States and Canada, and up to 1.5 million people died. Alone among the countries of Europe, Ireland experienced a declining population in the second half of the nineteenth century.

The Great Famine intensified anti-British feeling and promoted Irish nationalism: the bitter memory of starvation, exile, and British inaction burned deeply into the popular consciousness. Patriots of the later nineteenth and early twentieth centuries could call on powerful collective emotions in their campaigns for land reform, home rule, and eventually Irish independence.