Thank-you Ian. Although I do not agree with your attitude, I am on your side in this debate. You state quite clearly why the Queen should not have apologised. Feelings among Unionists and the Army are still too raw to allow it. The Irish might blame England for 800 years of oppression, but that's only because they have slanted their history to suit their current political purposes. They blame the English for callous murders of their people in the 20th century - Bloody Sunday is often cited, and David Cameron has issued an apology to the British people who were affected by this, but the soldiers involved, wrongly or rightly believed they were dealing with armed terrorists; Croke Park is often cited, but Croke Park was a misguided act of revenge for the greater act of murder committed by Michael Collins and his gang just hours earlier; the Easter Rising is often cited, but that was an open rebellion against the lawful government, and Pearse and his followers were committing treason in just the same way that the French Revolutionaries, the American Rebels or the Bolsheviks were in their time. I would venture to suggest that most acts of "suppression" by the English were carried out in order to preserve law and order in Ireland: it was violence and disorder they wished to suppress, not the Irish. Violence that the Irish are still committing against each other.
The Great Famine is often cited, too. The British did not cause the potato blight. In all probability, it was imported from the USA. And when the blight came to Ireland, it came to the rest of Europe too. To be fair, when pressed on the point, the Irish blame God the blight, but England for the Famine, which was worse in Ireland than anywhere else. While plentiful crops of corn were growing on Ireland's richer soils, England was importing that harvest for its own consumption, leaving the peasants to live off the poorer lands where only potatoes could grow. That England knew of the plight of the peasants in Ireland stands to its eternal shame, but it can plead in mitigation that, because of the very strong lobby of Irish landowners in the British Parliament at the time, the political will or the strength to do anything about it did not exist. Britain could have imported all the corn it needed from anywhere in the Empire - or the world, for that matter - but the Irish earls and lesser landowners of that country were making very nice profits by exporting corn to England and it was they, the Irish ruling classes, that ensured that this would continue to happen, rather than to be used to relieve their starving countrymen.
I offer no excuse for Cromwell other than that he - a traitor himself - was intent of suppressing any Royalist threat from Catholic Ireland. His decimation of the population cannot be justified, and Irish hatred for him - still alive - can be well understood. However, Cromwell's activities cannot be used to justify Irish terrorism today (nor are they, I hasten to add).
Events before that - the Tudor invasion, the Norman forces (Normandy was a viking state in France, by the way, which not only invaded Ireland, but conquered England too) are surely too far back to be relevant, just as the Irish invasions of Western England and Wales, where they plundered villages and churches and kidnapped people to be sold into slavery, including a certain Patrick from Wales, are no longer actions that the Irish should apologise for.
So I contend that England has only to apologise for failing to ensure that Ireland's great landowners put the well being of their tenants before profit. All of the rest, the Irish brought on themselves. That apology would never be accepted, for the Irish state is built on the myth of English oppression (like other nations I could mention) and an acceptance would be admission of the lies they base their legitimacy upon.