(CNN) -- It is a state visit that many in Ireland believed would never happen. But when the UK's Queen Elizabeth II lands in Dublin on Tuesday it will mark the reconciliation between two neighboring countries that once viewed each with suspicion and hostility.

Ireland's fight to free itself from its former imperial master is likely to form much of the narrative of the visit, the first by a UK monarch to the republic since it gained independence in 1922.

There will be constant reminders of the violent past. Her plane will touch down for example at Casement Aerodrome, a military airfield named after Roger Casement, who was executed for treason in 1916 for conspiring with the Germans. His fate was sealed when the queen's grandfather George V refused to commute his death sentence.

Like all foreign heads of state, the queen will then go to Dublin's Garden of Remembrance where she will pay her respects alongside Irish President Mary McAleese to "all those who gave their lives in the cause of Irish Freedom."

She will travel to another nationalist shrine, Croke Park, where British troops opened fire on a crowd watching a Gaelic football match in November 1920, killing 14. The massacre was sparked by the murder of 14 British intelligence officers by the IRA.

The Irish war of Independence that the killing was a part of directly led to partition of Ireland in 1921. The majority of the island gained independence but six of the nine counties of the province of Ulster chose to stay in the United Kingdom, eventually becoming the country of Northern Ireland.

In the late 1960s the conflict between mainly Protestant unionists who want Northern Ireland to remain part of the UK and largely Roman Catholic nationalists who want the North to be reunited with the rest of Ireland exploded into a political and sectarian war, known as the Troubles.

The three decades of ensuing violence between the IRA and loyalists claimed the lives of more than 3,000 people, most of them north of the border, and while the Good Friday Agreement effectively ended the conflict, suspicions remain, and for this reason the queen's state visit is more than symbolic.

Under the terms of the landmark accord, terrorist groups on both sides dumped their weapons, and political allies of both sides now work together in Northern Ireland's power-sharing government.

The change has been so rapid that even as recently as the late 1990s one journalist said he could never have imagined a state visit by the queen. Toby Harnden, who covered Ireland for the Daily Telegraph, said while some people on both sides still have their doubts over it -- for different reasons -- more significant is the peaceable language used in the debate.

"Some Catholics will see this as Britain cementing its claim over the Irish territory of the six counties of Northern Ireland," Harnden told CNN. Meanwhile "the Protestants will see the queen's visit as ratification of a state that they believe is constitutionally hostile to any British presence in Ireland. So on both sides there'll be qualms."

But the comment by Gerry Adams -- a pivotal figure in Northern Irish history as long-time leader of Sinn Fein, the IRA's political allies -- who said the queen's visit was "premature" speaks volumes, Harnden said, compared to incendiary language he had used in the past. For instance, "when the queen's cousin Lord Mountbatten was killed by the IRA in 1979 (Adams) said it was an execution that was fully justified."

"When I was there the IRA cease-fire had collapsed, there was violence and killings, no surrender, no compromise. In those days there was no likelihood of the queen ever visiting."

The spur for the change, Harnden believes, was the establishment in 1998 by former UK Prime Minister Tony Blair of a public inquiry into the 1972 Bloody Sunday massacre, in which British troops shot dead 13 people at a civil rights march in Londonderry. The death of another man four and a half months later was also attributed to the injuries he received on that day.

"Bloody Sunday was a running sore, so the fact that Blair had a full inquiry was a surprise. And to have Conservative prime minister (David Cameron) stand up in parliament (in 2010) and apologize for what happened in 1972 was a significant moment in Irish history. The Catholic community didn't think there would be such a comprehensive dig back into history."

Without denying the benefits of peace, others in Ireland believe the queen's visit is long overdue, with the two countries having enjoyed good relations for many years.

They believe the visits by the queen and U.S. President Barack Obama the following week, security for which will cost 30 million euros ($42 million), is a distraction for a nation that has suffered a brutal downturn since the collapse of the "Celtic Tiger" economy in 2007.

Roy Foster, professor of Irish history at Oxford University, said the queen may even ask some pointed questions to Irish leaders about their handling of the recession.

"I think the visit is overdue and it seems to be the right time now," Foster told CNN. "Ireland needs some type of distraction, if not bread and circuses. The country is in a bad state: thanks to incompetent, corrupt and compromized politicians, criminal bankers and supine government regulators, we are now in hock to European financial institutions.

"I think the queen famously asked some representatives of the city of London, why did you not see all this financial meltdown happening, it would be quite amusing if she asked one of the Irish politicians that."

Foster said amid the recession London seemed friendlier than countries in mainland Europe. "The Irish look grimly at the French and Germans now because they imposed such conditions for the so-called bail-out which was an extremely hard bargain driven by powerful financial interest which will mark and I think cripple the Irish economy for years to come.

"Given these conditions imposed by our friends in Europe, the British look like better friends than the Germans these days," Foster added.

CNN's Fionnuala Sweeney and Journalist Peter Taggart contributed to this report.