Túath
Túath (plural túatha) was a medieval Irish polity smaller than a kingdom. The word is from Old Irish and is often translated as "people" or "nation". It is cognate with the Welsh and Breton tud (people), Galician toudo, and with Germanic þeudō (for which see theodiscus).
"Túath" referred to both a geographical territory and the people who lived on that territory. In Modern Irish, it is spelled tuath, without the fada (length mark), and means "countryside".
In ancient Irish terms, a household was reckoned at about 30 people per dwelling. A trícha cét ("thirty hundreds"), was an area comprising 100 dwellings or, roughly, 3,000 people. A túath consisted of a number of allied trícha céta, and therefore referred to no fewer than 6,000 people. Probably a more accurate number for a túath would be no fewer than 9,000 people.
Social organization
The organization of túatha is covered to a great extent within the Brehon laws, Irish laws written down in the 7th century, also known as the Fénechas.