Number of T atha Does anybody have any knowledge of how many t atha there were in Ireland Obviously it was constantly changing but does anyone know the average number through the period they existed I remember hearing from school that there was about 100 t atha in Ireland in the middle ages And if as this article says a T ath had about 10 000 people that would mean about 1 million on the whole island which sounds about right from what I ve heard of population estimates of the time So should I just add in the 100 figure as I do distinctly remember being told that number in school