Thomas, son of Henry IV., viceroy, [87]
— St., of Dublin (Thomascourt), [317]
— St., of Acon, [198]
Thomastown, [59], [167], [388]
Thomond, or Clare, [63], [65], [124], [172], [175], [203], [204], [218], [219], [227], [261], [271]
— Murrough O’Brien, first Earl of, son of Tirlogh Don, [227], [256]-[258], [270], [271], [338], [345], [346], [349], [353]
— Donough O’Brien, second Earl of, son of Connor, [173], [191], [192], [200], [201], [204], [227], [228], [256], [258], [270], [271], [393]
— Connor O’Brien, third Earl of, son of Donogh, [393], [402], [409], [410]
Thorstein, [28]