Hundreds of thousands died in Ireland in the mid-1840s because:

1. Ireland's poorest peasants had become dependent on the potato. 2. When disease destroyed the potato crop in the mid-1840s, hundreds of thousands died of starvation. 3. The event is remembered as the Great Irish Potato Famine. _Source: NCERT Class 10 Social Science, 'India and the Contemporary World II', Ch 3 'The Making of a Global World'_