Iu2019ll try not to repeat too much of what is said in the previous answers. The Irish potato famine was of course a natural disaster u2023 between 1845 and 1852, an infection repeatedly destroyed the potato crop on which much of the population was dependent. But more important, it was a failure of government, both in terms of long-term policies that made a humanitarian disaster inevitable and in terms of an abysmal response to the disaster when it struck. In the circumstances, any government (libertarian or otherwise) would have had an obligation to ameliorate the immediate suffering, what a libertarian government could do in the long run is to promote human liberty so that nothing like the famine happened again.Rob Weir and others have pointed to the British governmentu2019s role in creating the conditions that led to the famine, including as the 17th century confiscations of land (in 1600, almost all land in Ireland was owned by Irish Catholics, by 1700, only about 4 percent was), and the Corn Laws. But perhaps even more pernicious were the effects of the Penal Laws, a series of sectarian measures enacted after the defeat of the Jacobites in 1691 that were only finally repealed in 1829.These laws were designed to reduce Catholics to penury and to keep them that way. For example, Catholics were barred from education, excluded from most professions, and subject to limits on the value of personal property that they could own. But particularly devastating from the perspective of the eventual famine, a Catholic landowner or leaseholder (with the latter being greatly in the majority) was forced by law to divide his holdings equally among all his sons on his death. Thus, with each successive generation, holdings became progressively smaller and the Irish tenant farmers progressively poorer. The potato offered an advantage in that even a tiny patch of bad land could yield a large enough crop to keep a family alive.In short, even if there had never been a potato blight, a demographic catastrophe u2023 caused entirely by long-term, malicious government policy u2023 was inevitable. The potato blight was just the match, the bonfire had already been set. Now, unlike many libertarians, I am not opposed to government intervention in cases of genuine natural disaster. Sometimes, only governments have the resources to act quickly enough and on an appropriate scale in the wake of an earthquake or tsunami. But surely everyone this side of Ayn Rand would agree that the government should act when a humanitarian disaster is the direct result of the government's own policies.Finally, I think it a bit obtuse to suggest, as another answer did, that the problem was not that the Irish lacked food but rather that they had no money to buy food. The peasants had no money because of the same government policies that drove them into subsisting on a potato monoculture. They labored on a landlordu2019s farm (which often had been their grandfatheru2019s land), in return for which the landlord leased them a patch of ground on which they grew the potatoes that were their sole means of subsistence. Of course they had no money to buy food. They had no money, period.