In his later years Manus was troubled by quarrels between his sons Calvagh and Hugh MacManus; in 1555 he was made prisoner by Calvagh, who deposed him from all authority in Tyrconnel, and he died in 1564.
Manus was several times married.
Hugh Roe O'Donnell (1572-1602), eldest son of Hugh MacManus O'Donnell, and grandson of Manus O'Donnell by his second marriage with Judith O'Neill, was the most celebrated member of his clan.
The largest, Manus, is about 60 m.
Most are of coral formation, but the hills of Manus are believed to be extinct volcanoes.
