brother Diarmuit took advantage of the High King's misfortune to steal the Kingship and banish Muirchertach. However, the next year, Muirchertach miraculously regained his strength and returned to his home, from whence he launched campaigns against Diarmuit. He finally managed to capture his rebellious brother in 1115, but his High Kingship seemed to be disintegrating. The young Toirdelbach Ua Conchobhair, King of Connacht, son of Muirchertach's old rival Ruadhrí na Saide Buide, and Muirchertach's nephew, at only twenty-seven years of age, was making quite a name for himself in the political landscape of Ireland. He launched repeated invasions of Munster, which Muirchertach struggled to repel in his weakened position. Muirchertach was further weakened by rebellions by the MacCarthy Mór dynasty in southern Munster, who had been living under the rule of the O'Brien dynasty for over a century. These rebellions were supported by Ua Conchobhair, who managed to successfully invade and partition the Kingdom of Munster in 1118. Muirchertach died in 1119 and the Annals of Ulster call him 'king of Ireland and tower of the honour and dignity of the western world." Munster was divided into three Kingdoms: the Kingdom of Thomond under the O'Brien dynasty, the Kingdom of Desmond under the MacCarthy Mór dynasty, and the Kingdom of Airgíalla under the Kennedys, although the last was short-lived. Muirchertach apparently went into retirement having lost his High Kingship, and died at Lismore, modern County Waterford, a year later in 1119. He was succeeded by Toirdelbach Ua Conchobhair as High King of Ireland, who would prove to be one of the greatest High Kings in the history of Ireland. Although the O'Briens never reclaimed the High Kingship, the Kingdom of Thomond remained a powerful kingdom for the next few centuries. Assessments Anthony Candon (1979, p. 398) remarked of Ó Briain: Muirchertach Ó Briain was an ambitious, modernising and outward-looking king whose goal was to make himself king of Ireland as much as William Rufus and Henry I were kings of England; in reality his position was, perhaps, more analogous to that of Philip I in France ... but his actual authority in Ireland, especially at the height of his power in the first years of the twelfth century, greatly exceeded that of Phillip in France. ... Ua Briain ... pursued a vigorous foreign policy which was to carry his activities beyond his own shores. In the latter regard, Candon (1979,