Vikings established a fortified base at Dublin. Known as longphorts, these were fortified bases which the Vikings could use as ports for their ships and from where they could launch raids.

The Vikings laid siege to Dumbarton Rock. The siege lasted for four months after which the defences fell and the Vikings took prisoners and treasures to Dublin.

Ivar 'the Boneless', the king of Dublin died. He was succeeded by his brother Halfdan.

The Norse that had occupied Dublin were expelled with nowhere to go. Over the next few years they attacked Wales, Scotland and North West England.

When Sihtric died he left an heir Olaf. The king of the Norse in Dublin arrived to assist Olaf but Athelstan was ready for any trouble that they could do and defeated them. York was seized and its fortifications destroyed.

Richard de Clare, the Earl of Pembroke, invaded Ireland with 200 knights in armour and up to a 1,000 foot-soldiers capturing Waterford easily and then Dublin on behalf of Dermot, the King of Leinster.

Dublin fell to the Norman army. ^[1]

After letting the population of Dublin leave, the Earl of Pembroke and his men spent the Winter in the city. ^[2]

King Henry II travelled to Ireland to receive the homage of the Irish leaders. Traders were invited to Dublin where a colony of English was set up. Henry stayed in Ireland over the winter months returning to England in the spring of 1172. ^[3]

A 'Winter Palace' was constructed in Dublin where King Henry II celebrated Christmas. ^[4]

The Treaty of Windsor was signed by King Henry II and Rory O'Connor allowing O'Connor control of the areas of Ireland other than Leinster, Meath, Waterford and Dublin which were controlled by the English King. O'Connor agreed to pay Henry an annual sum of money and to provide one hide from each ten animals slaughtered every year. ^[3]

John de Courcy, a Norman knight with an army of around 320 men from Dublin, attacked the area of Ulidia now Ulster and captured its capital town Downpatrick. The king of the area, MacDunlevy, attempted to retake the town but was beaten back by de Courcy.

King John ordered the construction of a castle at Dublin.

Archbishop John Lech obtained a Papal Bull from Pope Clement V authorising the foundation of a university at Dublin but died before he could complete it's foundation.That was left to his successor.

The Statute of Staples. A law that fixed 15 towns as staple towns. A staple town was a town that was restricted in what it could sell to foreign merchants. The towns were Bristol, Canterbury, Carmarthen, Chichester, Cork, Drogheda, Dublin, Exeter, Lincoln, London, Newcastle, Norwich, Waterford, Winchester and York.

King Richard II gave the title of Marquis of Dublin to his favourite, Robert de Vere. This gave de Vere power over all royal lands in Ireland, and made him almost as powerful as Richard's uncles.

The Duke of York sailed for Ireland, landing at Howth, Dublin.

Lambert Simnel arrived in Ireland claiming to be Edward Plantagenet, Earl of Warwick, one of the young boys who had been locked up in the Tower of London by Richard III because they were rivals to the English Crown. John de la Pole, Earl of Lincoln who himself had a claim to the throne backed Simnel's claim and raised funds and an army. When they landed in Ireland Simnel was crowned by the Irish at Dublin as Edward VI. ^[5]

A rebellion of Irish Catholics in Ulster erupted. They attacked the Protestants who were living in the area. The rebellion targeted Dublin but was unable to take the city.