The potato was introduced to Europe sometime in the 16th century. There are many theories on how it arrived, but the one with the most credibility is from a case study done by Theresa Purcell. She explains how the white potato, also known as the Irish potato, originated in the Andean Mountains and was brought to Europe by the Spaniards. The potato was originally classified in the same family as the poisonous nightshade so people refrained from eating it (1). During the middle of the 18th century, European monarchs discovered the nutritional value of the potato and ordered that it be planted (2).
By the beginning of the 19th century the potato had taken root in most of Ireland, becoming the staple source of food for 90% of the population (Purcell, 2). The main reason for this is because the potato could support a family on a very small plot of land, and could be grown in almost any soil type and climate. To see why this was important you have to look at a little bit of pre-famine history in Ireland. After the Napoleonic Wars, Ireland was considered part of the United Kingdom. A lot of control over Ireland was exerted by the British, including landholdings. The system of landholdings was set up with a landlord who owned a huge section or land, even though he may not have even lived there. Purcell explains that these landlords, almost all of whom were protestant, controlled nearly 95% of the land (3). The landlord would have a few farmers or agents, usually British or wealthy Irish protestant, who were in charge of different plots of his land. Those farmers would then either hire Irish peasants to work the land in exchange for a small plot of their own to live and farm on, or they would divide up their land and give small plots to Irish peasants who would have to pay them taxes. A lot of these peasants didn't even have large enough plots to be thought of as land owners. Figure #1 shows a map of the percentages of people who owned large portions of land (rated usually landlords or wealthy farmers), Holdings < ₤4 (Mostly peasants who owned a couple acres of land) and those who held no land (peasants that held very little land, migrant workers, etc ) (O Grada, 131) Figure #1
Either way, a peasant would have to sell a large portion of their crop to pay the taxes, or they would have to spend most of their time working in the landlord's fields. In the book Irish History and Culture, the editor explains that the number one reason for the potato becoming so important was that a small section for potatoes could support a family and their livestock. The potato allowed families to survive on these small plots, which in turn also contributed to an increase in the population. Figure #2 shows the increases in population from 1687 until the census in 1841.
YearPopulation Size, in ThousandsGrowth, in ThousandsNumber of YearsPercentage Growth, Total 16872,167
The increasing population made things even worse. As the population grew, more and more land was subdivided and thus increasing the dependency on potatoes. The landlords liked the subdividing because they could charge more taxes. The peasants liked it because they were able to have more plots of land to give to their sons when they got married., which wouldn't have been possible if it weren't for the potato. It also allowed peasants and landlords to expand to previously un-inhabitable land because they potato could be grown there (195-197).
Before the famine of 1845, there were several other blights that affected the Irish. From 1740-41 there was a famine that killed nearly a quarter of a million people. There was another two year blight from 1815-17, and a food shortage in 1822....