Queen pays homage to fallen Irishmen

She toured the city's spectacular sporting arena in the latest engagement of an extraordinary royal visit to the republic.

It was at Croke Park that British forces opened fire at a match in 1920, leaving 14 people dead.

The visit comes on day two of her trip to Ireland and is among a series of milestones.

The monarch earlier laid a wreath alongside President Mary McAleese at the Irish National War Memorial in Islandbridge during a ceremony building on symbolic reconciliation.

She laid wreaths in memory of the men and women who died fighting for independence, and the 49,000 Irish soldiers killed in World War I.

The Croke Park atrocity, an apparent a revenge attack after 14 British intelligence officers were killed by the IRA, was the first in Ireland to become known as Bloody Sunday .

The Queen and Prince Phillip prepared for the visit by earlier calling in at the Guinness Storehouse, where they watched the "perfect pint" being poured by a master brewer.

Both declined the offer to have a taste of the black stuff.

But Prince Philip made a characteristically frank remark upon being shown one of the company's most famous artefacts.

Referring to the 9,000-year lease that founder Arthur Guinness signed for an old, disused and dilapidated brewery at St James's Gate, the Duke asked: "What kind of mug signs that?"

On Tuesday the Queen laid a wreath at the Garden of Remembrance honouring all those who died in Ireland's fight for independence in the early part of the 20th century.

The royal party also attended a private viewing of the Book of Kells at Trinity College.

The first official royal visit since independence occurred amid the biggest security operation ever mounted in the state, with thousands of police and armed soldiers on the streets of the capital.

Despite groups of well-wishers on some routes, the royal couple did not meet the public at any stage and it is unlikely they will at all this week.

Croke Park is the home of Ireland's Gaelic Athletic Association, which pledged to give the Queen a warm greeting.

The Queen was shown out on to the stadium's pitch and was later shown Gaelic dancing.

British Prime Minister David Cameron will also join the Queen for part of her trip, after holding talks with Irish prime minister Enda Kenny .

They and the Duke of Edinburgh will later attend a state dinner at Dublin Castle hosted by President McAleese in honour of the royal couple.

The monarch will give her only speech of her four-day state visit during the banquet.

Irish police are braced for further disruption after the Queen's arrival was marred by protests in the capital and 21 people were arrested on public order offences.