The more anti-Norman Irish lords began to realise that they had a chance against the Normans again. Aided by hired mercenaries from Scotland, called the 'Gallowglasses', they began to attack the property of the Norman Lords. In 1261, the Normans of Kerry were defeated and the O'Connors defeated the Normans of Connaught in 1270. And in 1274, the Normans of Wicklow were defeated. By 1300, large chunks of Ireland were once again ruled by the Irish Lords. The Norman King did not regard Ireland as strategically important (aside from trading goods) and was not prepared to waste his forces protecting the Normans there.

Until this point, the Norman kingdom consisted only of England and the lands in Ireland. In 1296, however, King Edward 1st of England sought to expand northwards and invaded Scotland. He took control, and removed the Stone of Scone (an important royal treasure of the Scottish Royal family that was finally returned 700 years later in 1996). For 10 years the English-Normans ruled the Scots. In 1306, however, a Scot named Robert Bruce hatched a plot to regain Scottish independence and with help of some Scottish lords, he defeated the English at Bannockburn in 1314. The victorious Robert Bruce then became King of Scotland.

The Irish Lords in Ulster, O'Neill and O'Donnell, were impressed by this turnaround in Scotland and wondered if Bruce could help them defeat the remaining Normans in Ireland. Robert Bruce knew that the English got many supplies from Ireland so the two sides worked out an agreement whereby Robert's brother, Edward Bruce, would become High King of Ireland in return for military assistance. Edward landed at Larne in Ulster (just north of present day Belfast) in 1315 with a large army, rapidly defeated the Normans of Meath and then continued southwards. However, many Irish didn't like him because he disrespected the Irish peasants and damaged their property by marching through it rather than going around it. Edward, nonetheless, was crowned King of Ireland in May 1316. Edward was joined by Robert Bruce later that year, and the brothers marched on the Normans of Limerick, Tipperary and Kilkenny and plundered their property. Robert returned to Scotland but Edward was finally defeated and killed by the Normans on 14 October 1318. Although the Bruces were gone, the Normans were weakened and the Irish now felt able to defeat them themselves. The pestilence of the Black Death of 1348 merely added to the decline of the Normans.

In 1360, King Edward 3rd finally realised that he was on the verge of losing control of the last Norman parts of Ireland and sent his son Lionel to try to reverse the declining trend. He arrived in Dublin in 1361 with an army and recruited local Normans. He then launched a series of unsuccessful offensives into Leinster and Munster. Faced with no good news to come home with, he held a conference in 1366 called the "Parliament of Kilkenny". This conference was designed to pass legislation for the Norman-controlled parts of Ireland, and attempted to reverse the trend of Norman decline by separating Irish and Norman culture. The laws passed banned Normans from marrying Irish, speaking Irish, using Irish law or dress, and listening to Irish music or stories. However, few Normans obeyed the laws - the families of many had been in Ireland for 2 centuries, and no longer felt patriotism towards England. Lionel died in 1367, with not much success to his name.

Richard 2nd became King in 1377. He landed at Waterford with a massive force of 10,000 men and a new invention: artillery. Faced with such a force, many major Irish Lords submitted to the English. Richard let these men hold their land if they promised loyalty to the English king. The Irish Lords of Leinster, however, were evicted from their estates and plans were made for English Lords to be set up instead. The land was temporarily left unoccupied, but as soon as Richard left in 1399 war broke out. The Irish Lords of Leinster returned to their land in Leinster and Richard's viceroy was murdered. Not long afterwards Richard was murdered by his cousin Henry who took the throne of England as Henry 4th.

The Norman decline continued for the next half century. By 1450, English control in Ireland had been reduced to a 20 mile wide strip around Dublin, known as the Pale. The English defended this land, and the Irish were unable to completely drive the English off the island. The Pale was surrounded with a fence to keep out the Irish. (This is where the phrase 'Beyond the Pale' comes from.) The 3 major English Lords whose estates were within the Pale continued to exist, and formed alliances with the neighbouring Irish and became very powerful. Outside the Pale (particularly Munster), former Norman Lords had practically become Irish, and many of them joined with the native Irish in their hatred of the English.