(1569–1626). A grandson of Calvach O'Donnell, he sided with the crown in the Nine Years War, backing Docwra's landing at Derry against Red Hugh O'Donnell after being promised a grant of Tirconnell. However, the post-war settlement favoured Hugh's brother Rory. Their mother Finola MacDonnell implicated Niall in Cahir O'Doherty's revolt (1608). After an Irish jury refused to convict him, he was detained for the rest of his life in the Tower of London.
From The Oxford Companion to Irish History in Oxford Reference.
Subjects: European History.