Britain's Queen Elizabeth II talks with Irish President Mary McAleese during welcoming ceremonies at Aras An Uachtarain, the Irish President's residence in Phoenix Park, Dublin, Tuesday May 17. (John Stillwell/AP)

Real and hoax bombs were found in Dublin Monday night, both believed to be planted by Irish dissidents opposed to compromise with Britain. No group claimed responsibility for either threat.

The queen’s four-day state visit will symbolize the conclusion to Northern Ireland's peace process and usher in a new era in relations between Britain and the Republic.

A man holds a placard to protest against Britain's Queen Elizabeth's visit to Ireland, in Dublin May 17, 2011. (JOSE MANUEL RIBEIRO/REUTERS)

“But the peace process has slowly taken root in Northern Ireland following events such as the Good Friday peace accords in 1998, and the Irish Republican Army’s decommissioning of weapons in 2005,” she writes.

Splinter groups opposed to the Northern Ireland peace agreement in 1998 are still active in the province, but t he Irish Republican Army has mostly given up its armed struggle after a bloody 30-year campaign for a united Ireland.

The visit will be biggest security operation in history of Ireland, which is determined to ensure the smooth success of the momentous visit.

Queen Elizabeth and her husband, Prince Philip, were greeted Tuesday by an Irish Army honor guard before boarding a bombproof, bulletproof Range Rover to have lunch with Irish President Mary McAleese. More than 8,000 police, two-thirds of the entire country's police force, shut down main roads in central Dublin and set up pedestrian barricades for several miles.

 Irish President Mary McAleese, who invited the queen, told Ireland’s RTE broadcaster that the royal visit was “an extraordinary moment in Irish history, a phenomenal sign and signal of the success of the peace process.”

Many tweeted about their excitement and nervousness about the visit:

The Queen is on a visit to Ireland. I haven’t felt this tense since I saw Obamas inauguration.less than a minute ago via ÜberSocial Favorite Retweet ReplyProfessor Wallofski