A branch within the royal
Uí Briúin (
Uí Briúin Aí) dynasty, the tribe of Síol Muireadaigh consisted of all the descendants of
Muiredach Muillethan, a 7th-century
King of Connacht. The term
Síol denotes the
seed, or
descendants, of Muiredach. According to historian C. Thomas Cairney, the Síol Muireadhaigh were the chiefly family of the Uí Briúin tribe of Connachta who in turn were from the
Gaels, the fourth and final wave of
Celtic settlement in Ireland which took place during the first century
BC. The major division within the tribe was between the descendants of Muireadhach's two sons,
Indrechtach and
Cathal (a quo Clann Cathail), who would both go on to become Kings of Connacht. Síol Muireadagh's parent dynasty, the Uí Briúin, held the
Kingship of Connacht, with one exception, for over 700 years (696–1474). The vast majority of Uí Briúin kings were members of the Síol Muireadaigh, whose power reached its peak in the 12th century when
Toirdhealbhach Mór Ua Conchobhair was recognized as
High King of Ireland. Toirdhealbhach's son
Ruaidri mac Tairrdelbach Ua Conchobair, would go on to succeed him, becoming last the
Gaelic High King of Ireland. ==Clann Cathail==