During the 12th century, the major cities in Ireland were Dublin, Waterford, Cork and Limerick. All four were founded centuries earlier by the Vikings as port towns and by now had developed into the principal merchant centres in Ireland. As well as providing Irish kings with trading links across Europe, they were also an important source of Viking mercenaries and ships. They were still Viking strongholds by the time the Anglo-Normans arrived, who immediately recognised their strategic importance. By 1170, Dublin and Waterford had already fallen to Strongbow and would remain in English control for centuries to come. Limerick was next on their sights. The man who directed the attack was Meiler fitzHenry, cousin of Henry II. It is said that as he led the charge on the city walls, he drove his horse into the River Shannon, calling on St David of Wales for protection. The city fell and the Anglo-Normans had gained a strategic foothold deep in Munster. However, they had outstretched themselves, and when their soldiers were needed elsewhere, they left the city in the hands of the local Irish king, Domnall Mór Ua Briain, king of Thomond (north Munster), comprising much of present-day Limerick, Clare, Tipperary and north Kerry. 

Domnall Mór Ua Briain was a grandson of Diarmaid Ua Briain, a brother of Muirchertach who had granted the Rock of Cashel to the church in 1101. He was married to Órlaith, a daughter of Diarmaid Mac Murchadha, and had come to power in 1168, shortly after Diarmaid returned to Wexford from exile in England. In effect, this meant that he was related to Strongbow through marriage. Domnall Mór Ua Briain does not appear to have been entirely averse to the presence of the Normans. In 1171 he met Henry II and formally submitted to him on the banks of the River Suir near Cashel. Since the days of Brian Boru, his family had controlled the Viking stronghold and port at Limerick. His views on the Anglo-Norman taking of Limerick are unclear, but no doubt he was uneasy about their presence deep in his kingdom. When the Anglo-Normans decided to leave Limerick, it seemed logical to appoint Domnall Mór to take charge until their return. However, according to tradition, no sooner had they crossed the bridge across the Shannon, as they looked back to the city they saw the gates being locked and the bridge broken. Their foothold in north Munster was gone, and so too any aspirations of a swift conquest here that might compare with Hugh de Lacy’s settlement of Meath, or John de Courcy’s invasion of east Ulster.

However, the fertile lands of north Munster were too tempting for the Normans to resist for long. In 1174, Hervey de Montmorency, who had arrived at Bannow in 1169, led an attack into Munster. He was heavily defeated by Domnall Mór Ua Briain and forced to retreat. Instead, the Anglo-Normans turned their attention further south. Having consolidated themselves around Waterford since their arrival there in 1170, they marched west towards Cork in 1177 under the leadership of Robert fitzStephen who had led the landing at Bannow Bay in 1169. Now the Anglo-Normans controlled another Viking port town as well as much of south Munster (Desmond). In so doing, they had undermined the ruling Meic Carthaig who had been the main competitors of the Ua Briain for the kingship of all Munster. Perhaps not surprisingly then, Domnall Mór Ua Briain did not stop the Anglo-Normans from attacking the heartlands of his old rivals in Cork. He watched from the side-lines, content with the fact that he had little difficulty in keeping the newcomers out of north Munster, where life continued much as it had before. Around 1184 Domnall Mór founded a Cistercian Abbey at Kilcooley, Co. Tipperary, and around 1189, he founded a nunnery at Killone, Co. Clare. In addition, he was an important patron of the Cistercian abbey at Monasternenagh, near Croom, Co. Limerick, founded by his father in 1148 as a daughter house of Mellifont. He was also a builder of castles, and some of the remains at Adare castle in Limerick are attributed to him.

During the early years of the invasion, the Anglo-Normans had limited resources in Ireland. They simply did not have enough bodies on the ground to expand west, especially after John de Courcy’s bold move into Ulster. For the time being they needed to prioritise the consolidation of the lands they had won in the east. Every so often, however, they tested the waters by marching into north Munster. Invariably they were pushed back. This would change after Lord John’s visit to Ireland in 1185, which re-energised the Anglo-Norman foothold in Ireland and attracted a new wave of administrators, wealthy settlers and military men.

While he was in Ireland, Lord John ordered the construction of a castle on the banks of the River Suir at Ardfinnan, Co. Tipperary. This was a clear sign of his intention to move the Anglo-Norman conquest deeper into Munster. Recognising this, Domnall Mór Ua Briain was quick to attack the castle while John was still in Ireland. Shortly before he sailed from Waterford at the end of his 1185 visit to Ireland, John made two important grants of lands in north Munster. These were entirely speculative grants, made on the understanding that they would become reality once they had been conquered by the two men who now received them. The two men in question were Theobald Walter and William de Burgh. Theobald Walter was the son and eventual heir of Hervey Walter of Amounderness in Lancashire in the north of England, and hereditary butler of the king of England. Theobald’s brother Hubert was Archbishop of Canterbury and had served as chief justiciar of England. In time, the family would become better-known as Butler, and for centuries they were one of the most influential families in Ireland. William de Burgh hailed from Norfolk in the east of England and he too had a younger brother called Hubert who later served as chief justiciar of England. The de Burgo family, better-known today as Burke, would also become a highly influential family in Ireland throughout the late medieval period.

Lord John’s grants to Theobald Walter and William de Burgh did not come into immediate effect. There was no four-day march comparable to John de Courcy’s alleged conquest of Ulster in 1177. Domnall Mór Ua Briain was too powerful. In fact, it wasn’t until 1192 that the Anglo-Normans made a concerted effort to move into north Munster when they erected castles at Kilfeacle and Knockgraffon to defend their newly conquered lands on both sides of the River Suir. These castles would be the bridgehead for a movement into west Tipperary and Limerick. Perhaps realising that he was running out of military options, Domnall Mór Ua Briain opted for the most common diplomatic manoeuvre of the period. He forged an alliance with William de Burgo, who he agreed should marry his daughter. This stemmed the tide, but only until 1194, when Domnall Mór Ua Briain died, and his three sons were unable to form an alliance strong enough to prevent the Norman advance west. Within a few years, the Ua Briain were forced west across the River Shannon into Clare. Here they remained for centuries to come, and continued to call their lands Thomond, but in reality this was a shadow of their former kingdom. Meanwhile, Theobald Walter and William de Burgh began to divide up the lands in Tipperary that Lord John had granted them before he left Waterford in 1185. By the time both men died around 1205, the landscape of Tipperary and Limerick had changed dramatically. About 1200, William de Burgh founded an Augustinian priory at Athassal, which was dedicated to St Edmund, a prominent English saint. Located on the banks of the River Suir, it may have been here that Domnall Mór Ua Briain submitted to Henry II in 1171. De Burgh died around 1205 and was buried in Athassal Priory. For over a century this would be the spiritual home and final resting place of the de Burgh’s in Ireland. Theobald Walter died in February 1206 at his castle at Arklow, Co. Wicklow, but chose to be buried at the Cistercian abbey he had recently founded at Owney in Co. Limerick, near the village of Abington.