It's a massive and hugely emotive issue. British (initially Anglo-Norman, then English) rule went back half a millennium before the potato became widespread, and more than three centuries before any European encountered the tuber. The Penal Laws enacted after the rebellions of the 17th century prevented Catholics (most of the Irish) from buying land, reducing most to rented smallholdings which in turn stimulated reliance on the potato, the crop most capable of supporting those with so few acres.

The potato was initially hugely successful, supporting a population growth at least rivalling England's, without the benefit of industrialisation - on the contrary, British interests successfully sought to stifle Irish industry whenever it threatened their own. There were occasional potato harvest failures with terrible consequences, but Ireland's population rose from around 2.5m in 1700 to nearly 8.5 million by 1845. The arrival of the productive but unappealing "lumper" variety around 1810 raised yields, but may have reduced resistance to infestation.

British policy during the Famine was atrocious. Policy-makers didn't want people to starve - not even the notorious Charles Trevelyan - but were more concerned to ensure that support wasn't excessive, than to see that it was sufficient. Famine relief was too little, too late. The question of allowing grain imports even split the governing party, giving rise to the two parties that would alternate in government for 80 years.

Some myths need dealing with at this point: Ireland exported food throughout the Famine, but more was imported, though far too little to address the crisis. Smallholders hadn't been forced to grow potatoes, it seemed a rational choice at the time and wasn't preferred by landowners, being a subsistence rather than a cash crop. British policy wasn't aimed at reducing population: if so it had been spectacularly counter-productive for many decades.

But it remains one of the darkest episodes in British history: between 800,000 and a million died under a government more concerned that its subjects should be kept in the habit of hard work than that they should be kept alive when disaster had reduced all their labours to nought. Ireland will never forgive it, neither should we. But we need to be wary of some myths too.

There were two different issues at play. The structure of the Irish economy was such that when the crisis hit it had a catastrophic effect on the poorest million of the population. Those living on tiny holdings were dependant on the potato to live. That wasn't a deliberate government policy but it was the outcome of a very uneven economic development.

As the Famine began, the initial government aid was quite extensive by contemporary standards but this did not continue for several reasons. A change of government brought in a more ideological approach, there was a lack of accurate information about the fact that the crisis was ongoing, a belief that Irish landlords should be paying for Irish relief developed as did a view that the Famine was a natural or divine outcome of the state of Ireland and no intervention could stop it doing its work. Finally there was compassion fatigue, people got bored of stories room Ireland (modern NGOs report the same problem today).

There is debate among historians as to what extent the British state could have mitigated the Famine. No one credible follows the traditional accusation of genocide but Christine Kineally is the most critical. Amartya Sen has put forward the idea that the cause of famine is not so much a shortage of food as it being seen as a commodity rather than a right. This fits the Irish case quite well. The ideology of the day was that if people were hungry it was up to them to buy food, not the state. Of the modern historians I would really recommend Cormac Ó Gráda who is both readable and a good economic historian. Avoid populist nonsense like Tim Pat Coogan whatever you do.

Relations with Britain over the period are better now in part because of the apology offered by Tony Blair in 1997. That goes into different territory of commemoration and the use of the past by the present.

The BBC have posted a series of pieces on this written by Peter Gray who is a superb historian. http://www.bbc.co.uk/guides/zqqqmp3