Explanation: Before the modern era, intermittent famines were a simple fact of life. Entire societies lived on relatively thin margins of survival, so any time a crisis or unexpected environmental effect came along, one could expect a reasonable chance of starvation following. Through the 17th-19th centuries, though, increasing agricultural yields in Europe and European colonies resulted in much less famine-prone societies - which is one reason why the Irish Potato Famine is so notable.
The Irish Potato Famine was kickstarted by crop failure, but its position in the 19th century as a high-casualty famine was ultimately a failure of governance - or of deliberate policy malfeasance, depending on whether you prefer to see British rule of Ireland as 'only' prejudiced and incompetent, or outright murderous. I take the former view, personally.
Effectively, what happened was that the 'free market' enthusiasts in the British government were certain that the market would 'self-correct' and that the Irish woes would be passing once the 'invisible hand' of the market took its course. Some charity efforts aside (and often with a horrific 'means-testing' involved which disqualified most farmers who held any survivable amount of land), the British government was content to let the situation 'resolve itself'.
Unfortunately, what these 'free market' enthusiasts didn't realize, or perhaps didn't care about, was that the entire 'invisible hand' metaphor for the free market is not a guarantor of ideal outcomes - the invisible hand metaphor simply describes how consumers and firms acquire the goods and services they require to function in the absence of a centralized plan. It does nothing to guarantee that those who receive the goods are the ones who need them most, only that the ones who receive the goods do desire them (a surprisingly legitimate issue in economic systems) and have the means to exchange equal value for them (ensuring systemic sustainability in scarcity). In other words - the 'invisible hand' metaphor only says that the market works in the sense that the gears keep turning and the system perpetuates itself without much effort from any given actor or firm - not that the market works for the common good.
For this reason, you have the extremely absurd scenario in which Irish folk who were quite literally starving to death were watching their region sell food to a region which was donating food to to Ireland to reduce starvation. The 'invisible hand' delivered food to the people who could pay the most for it at bulk prices - who felt a little pang of conscience at making 20% mark-up off the starvation of human beings, and sent a few measly percentage points back. For obvious reasons, being given a small amount of food is not really the equivalent of a large amount of food being drained from the Irish market - supply was reduced, demand remained the same, prices remained high, and starvation remained rampant.
Ireland was largely depopulated by this multi-year famine - in part by death, but in much larger part by emigration - and never recovered its early 19th century population numbers, even up to the present day.
