Cotter, cottier, cottar, Kosatter or Kötter is the German or Scots term for a peasant farmer. Cotters occupied cottages and cultivated small land lots. The word cotter is often employed to translate the cotarius recorded in the Domesday Book, a social class whose exact status has been the subject of some discussion among historians, and is still a matter of doubt. According to Domesday, the cotarii were comparatively few, numbering fewer than seven thousand people. They were scattered unevenly throughout England, located principally in the counties of Southern England. They either cultivated a small plot of land or worked on the holdings of the villani. Like the villani, among whom they were frequently classed, their economic condition may be described as free in relation to everyone except their lord.

The Great Famine, also known as the Great Hunger, the Famine and the Irish Potato Famine, was a period of starvation and disease in Ireland lasting from 1845 to 1852 that constituted a historical social crisis and subsequently had a major impact on Irish society and history as a whole. The most severely affected areas were in the western and southern parts of Ireland—where the Irish language was dominant—and hence the period was contemporaneously known in Irish as an Drochshaol, which literally translates to "the bad life" and loosely translates to "the hard times". The worst year of the famine was 1847, which became known as "Black '47". During the Great Hunger, roughly 1 million people died and more than 1 million more fled the country, causing the country's population to fall by 20–25% between 1841 and 1871. Between 1845 and 1855, at least 2.1 million people left Ireland, primarily on packet ships but also on steamboats and barques—one of the greatest exoduses from a single island in history.