A security operation costing more than ?6.2 million will be in place during the Queen?s three-day State visit to the Republic of Ireland next month.
Police fear Republican dissidents could use the historic tour as a backdrop to further terrorist outrages.
Their operations have been heightened by renewed terrorism - including a 500lb bomb found in a van on the border town of Newry last last week.
The Queen, accompanied by the Duke of Edinburgh, is scheduled to visit a number of sensitive sites which could play into the hands of extremists.
The Royals will travel to Dublin?s Garden of Remembrance dedicated to ?those who gave their lives in the cause of Irish freedom?
And an event will be held at Croke Park, home of the Gaelic Athletic Association and scene of a 1920 massacre when British troops opened fire on a crowd, killing 14 people.
Details of the Royal entourage?s itinerary were published as police stepped up their efforts to tackle a surge of violent dissident activity.
They fear terrorists want to target more police officers after the murder of Catholic Ronan Kerr in a car bomb attack outside his Northern Ireland home.
A van bomb packed with 500lb of homemade explosives was discovered abandoned in an underpass near the border town of Newry last Thursday.
Police said the wheelie bin device may have been intended for a town centre and could have caused deaths on the scale of the 1998 Omagh massacre.
Inquiries continue into a substantial arms and explosives cache uncovered by the murder investigation team in County Tyrone, earlier in the week.
The surge in activity has provoked condemnation across the political spectrum as thousands joined a peace march in Mr Kerr?s home town of Omagh yesterday afternoon.
Sinn Fein?s Martin McGuinness said terrorists face united opposition and urged communities to ?remain steady? against the threat.
He said evidence from recent years is that republican dissidents have ?limited capability? but added: ?You can?t rule out anything.?
Party president Gerry Adams said republican heartlands are ?seething in anger? at the violence and underlined that the ?the war is over.?
Police and MI5 officials are reviewing historic dissident attacks in a bid to ramp-up pressure on terrorists ahead of the State visit.
They have uncovered evidence of increasing links and co-operation between violent factions with relatively few members.
A special team of detectives is undertaking a cold case review of evidence using the latest fingerprint and DNA forensic techniques.
They are also sweeping police and security service databases for information that could link suspects to the latest wave of terror.
Detectives have been given extra time to question three men arrested in Northern Ireland and Scotland over the murder of Mr Kerr with a booby-trapped bomb on April 2.
The device detonated not long after a fun run had passed the scene and the victim may have been under surveillance by his killers.
It is believed that a police operation forced the latest bombers to abandon the latest bomb, contained a Ford Transit stolen near Dublin in January.
Hundreds of motorists drove past the deadly device unaware of the danger after traffic cones and warning signs had been removed, and even driven over, by others.
The Queen has visited Northern Ireland several times, including a visit to mark her Golden Jubilee in 2002.
Ahead of her 1977 visit the IRA promised to give her a ?visit to remember? and mounted a campaign of violence in a bid to get it cancelled.
As a result a huge contingent of 32,000 armed forces personnel and police went on duty in the then biggest ever royal security operation.
on top of the 6.2 mill -
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