Iddawc, the Agitator of Britain, [337], [338].
Ilbhreach, son of Manannán, [136], [140], [211], [222].
Illann the Fair, son of Fergus mac Roy, [193], [196]-198.
“Illusion, the Land of”, an old name for Dyfed, [279].
Indech, son of Domnu, a king of the Fomors, [48], [70], [83], [90], [108], [112].
Inniskea, the Lonely Crane of, [146];
stone worship in, [415].
Invasions, the Book of, [121].
Ioldanach, the “Master of All Arts”, a title of Lugh, [63], [85], [237], [239].