Fearghal Ó Taidg an Teaghlaigh, Chief of the Name, Marshal and bodyguard of King Cathal Crobhdearg Ua Conchobair of Connacht and his successor, Aedh, died 1226.
Ó Taidg was a descendant of King Tadg mac Cathal of Connacht (reigned 925–956), and was thus distant related to the Ua Conchobair (O'Conor) ruling dynasty.
His family were one of a number of septs of the Síol Muireadaigh, which included clans such as Geraghty (Mac Airechtaig), Moran, Flanagan, Mulrooney, and MacDermot.
The earliest record of the term occurred in 1132, when The castle of Bun-Gaillmhe (Galway) was burned and demolished by a fleet of the men of Munster; and a great slaughter was made of the people of West Connaught, together with Ua Taidhg an Teaghlaigh, and many other noblemen.
Donn Óge Mag Oireachtaigh had been deprived of his lands by Aedh, and now sought the help of Domnall Óg Ó Néill of Tír Eógain.
An oppressive malady raged in the province of Connaught at this time: it was a heavy burning sickness, which left the large towns desolate, without a single survivor.