Evidence has been found in the Lough Gur area shows that people were living more than 5,000 years ago. In Gaelic times, the region was part of the kingdoms of Thomond and Desmond. One of the treasures of Ireland's Celtic monastic heritage, the Ardagh Chalice, was found in western Limerick. After the Anglo-Norman invasion in the 1100's, families such as the de Burgos and FitzGeralds gained control of lands. Hundreds of castles were built. Limerick has more castles dating from the Middle Ages than any other Irish county. After periods of war in the 1500's and 1600's, the British government granted lands to British settlers, these plantations for various reasons only met with limited success.

The attractive village of Adare reflects some of the features of Limerick's history. It was a medieval foundation, and there are remains of a medieval castle, churches, and monasteries. The earls of Dunraven later remodeled the village, and built Adare Manor which is now a hotel. The road to Rathkeale passes through an area to which German settlers known as Palatines came in the early 1700's.

Limerick city was founded by the Vikings in AD 922 on King's Island and rapidly became a threat to the whole region, in 972 King Mahon of Thormond together with his famous brother Brian Boru defeated the Limerick Vikings at the battle of Solohead near Tipperary.

Muirchertach Mor O'Brian King of Munster (1086-1118) The Anglo-Normans developed it from the late 1100's. The first settlement was on an island in the Shannon that became known as Englishtown. On it are St. Mary's Cathedral and King John's Castle, which both date from the Middle Ages. The city is famous in Irish history for the Siege and Treaty of Limerick in 1691, during the Jacobite-Williamite War. The Newtown Perry district of wide streets and Georgian houses was laid out in the 1700's. It is now the main business district of the city.

Read about Limerick in 1837 from Samuel Lewis' Topographical Survey of Ireland.