The castle was attacked several times by the O'Briens (or O'Brians) and their allies. In 1284, while De Clare was away in England, the site was captured and destroyed. On his return, in 1287, De Clare had the site rebuilt and a long fosse built around it. The castle was again attacked but it did not fall until 1318. In that year a major battle was fought at Dysert O'Dea as part of the Irish Bruce Wars, in which both Thomas De Clare and his son Richard were killed. Lady De Clare, on learning this, fled from Bunratty to Limerick after burning castle and town. The De Clare family never returned to the area and the remains of the castle eventually collapsed. As the stones were likely used for other local construction works, no traces remain of this second castle. In the 14th century, Limerick was an important port for the English Crown. To guard access via the Shannon estuary against attacks from the Irish, the site was once again occupied. In 1353, Sir Thomas de Rokeby led an English army to conquer the MacNamaras and MacCarthys. A new castle (the third) was built at Bunratty, but once again, its exact location is unknown. Local tradition holds that it stood at the site where the Bunratty Castle Hotel was later constructed. However, the new structure was hardly finished before being captured by the Irish. Documents show that in 1355, King Edward III of England released Thomas Fitzjohn Fitzmaurice from prison in Limerick. He had been charged with letting the castle fall into the hands of Murtough O’Brien whilst serving as a Governor (Captain) of Bunratty. The fourth castle, the present structure, was built by the MacNamara family after around 1425. Its builder may have been one Maccon Sioda MacNamara, chieftain of Clann Cuilein (i.e. the MacNamaras). He died before the castle was completed which happened under his son Sean Finn (died in 1467). At around 1500, Bunratty Castle came into the hands of the O'Briens (or O'Brians), the most powerful clan in Munster and later Earls of Thomond. They expanded the site and eventually made it their chief seat, moving it there from Ennis. In 1558, the castle—now noted as one of the principal strongholds of Thomond—was taken by Thomas Radclyffe, the Lord-Lieutenant of Ireland from Donal O'Brien of Duagh, last King of Thomond (died 1579), and given to Donal's nephew, Connor O'Brien.