	In a series of conflicts between 1201 and 1204, de Courcy finally fell from power. By 1205 he was forced from Ireland altogether, and his lands were awarded to Hugh de Lacy, 1st Earl of Ulster (d. 1242). Sometime in 1205, de Courcy rose in rebellion, and gained military support from Affreca's brother, Ragnvald Godredsson (), King of the Isles. The "Chronicle of Mann" specifies that de Courcy's massive force was further strengthened by Rögnvaldr with one hundred ships. Together the two laid siege to what the chronicle describes as "the castle of Rath", before being beaten back with the arrival of Walter de Lacy (d. 1241), Hugh's elder brother. The expedition is also recorded in the "Annals of Loch Cé", which state that de Courcy brought a fleet from the Isles to battle the de Lacys. Although the expedition ultimately proved a failure, the annals note that the surrounding countryside was plundered and destroyed by the invaders. The identity of the castle noted by the chronicle is almost certainly Dundrum Castle, which was possibly constructed by de Courcy before 1203. The defeat of 1205 marks the downfall of de Courcy, who never regained his Irish-lands.