Clontarf became a significant location in Irish History, more than a century before the Castle was built. Brian Boru, the High King of Ireland, and the famous Battle of Clontarf, on Good Friday, 23rd April 1014, will always be associated with and central to the history of the Clontarf area.

Brian BoruIt all began when Mael Morda, King of Leinster, began to plot against Brian Boru. Mael Morda made an alliance with Sitric, the Viking King of Dublin, who was assisted by the Vikings of the Orkney Islands and the Isle of Man. Brian Boru marched against them and the great battle was fought at Clontarf.

It ended in victory for Boru's army. However, on the night of the victory, Boru was praying in his tent, surrounded by five men, who were guarding him. A small group of Vikings, who were retreating from the battle through a wooded area, close to the site of what is now Clontarf Castle, came across the guarded tent. Realising who was being protected; they killed all five guards and went on to kill Brian Boru, who by now was 72 years of age.

On 15th December 1641, the Puritan Republic General, Sir Charles Coote, led a troop of soldiers into Clontarf to quell the rebel activities. He found most of the ships cargo of weapons and ammunition in George King's Clontarf Castle. Then the massive sum of £400.00 was put on the King's head and the Castle was confiscated. Coote marched on to Swords and defeated Netherville and his rebel army.

ArmourOn 14th August 1649 Oliver Cromwell granted the estate to John Blackwell, who sold it to John Vernon, who was Quartermaster General of Cromwell's army here in Ireland. The Vernons were in Clontarf for almost 300 years, with a family motto of 'Vernon Semper Viret', which means 'Vernon always flourishes'. In 1660 John Vernon passed the Castle on to his son Edward. Edward died in 1684 and one of his sisters took over the castle. In 1695 a first cousin of Edward's, also named John Vernon claimed rights to the castle. An Act of Parliament granted the estate to him in 1698.

In 1835 the original building was unsafe and a distinguished Irish architect, William Vetruvius Morrison, was called in to survey the building. He perceived the problem as sinking foundations and the building was demolished. It was rebuilt and the castle as we know it, was completed in 1837.

In 1972, Gerry and Carmel Houlihan bought the castle and ran it as one of Ireland's best cabaret venues until April 1997, when the last cabaret show was staged.

The Castle was closed from June 1997 and reopened in June 1998, as a superb four-star hotel.