Cotter, cottier, cottar, Kosatter or Kötter is the German or Scots term for a peasant farmer (formerly in the Scottish highlands for example). Cotters occupied cottages and cultivated small plots of land. The word cotter is often employed to translate the cotarius of Domesday Book, a class whose exact status has been the subject of some discussion, and is still a matter of doubt. According to Domesday, the cotarii were comparatively few, numbering less than seven thousand, and were scattered unevenly throughout England, being principally in the southern counties; they were occupied either in cultivating a small plot of land, or in working 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 every one except their lord.
A cottar or cottier is also a term for a tenant renting land from a farmer or landlord.
Highland Cotters (including on the islands, such as Mull) were impacted by the Industrial Revolution, as landowners realized they could make more money from sheep than crops. The landowners raised rents to unaffordable prices, or forcibly evicted entire villages, leading to mass exodus and an influx of former cotters into industrial centers, such as a burgeoning Glasgow.
Cotter houses (Kate or Kotten) were detached houses near German villages, used as homes and workshops. Many of these Kotten/Cotter houses still remain.
A cottier in Ireland (c.1700–1850) was a person who rented a simple cabin and between one and one and a half acres of land upon which to grow potatoes, oats and possibly flax. The ground was held on a year to year basis and rent was often paid in labour. Usually, the land available to the cottier class was land that was considered unprofitable for any other use.
The cottier existed at subsistence level because of high rentals and the competition for land and labour. The more prosperous cottier worked for his landlord and received cash after rent and other expenses were deducted. There was no incentive to improve a holding as any such improvement usually prompted a rent increase.
During the early decades of the nineteenth century, the situation for cottiers worsened considerably as the population continued to expand and in turn led to the dramatic events of the Irish Famine of 1845–49. After the Famine, the cottier class almost completely disappeared. 
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