
Early Medieval Ireland
Political and social organization in Early Medieval Ireland

The Tuath
The basis of society in Early Medieval Ireland was the tuath (pluaral tuatha) the clan, or petty kingdom. The land was organized into a number of tuatha, each of which was quite independent under its elected king. Groups of tuatha tended to combine, but the king who claimed overlordship in each group had a primacy of honour rather than of jurisdiction.
There was not a king of all Ireland (árd rí Éireann) until the tenth century. However, a division of the country into five groups of tuatha, known as the Five Fifths (Cuíg Cuígí), had occurred about the beginning of the Christian era. These were Ulster (Ulaidh), Meath (Midhe), Leinster (Laighin), Munster (Mumhain), and Connaught (Connacht).
The king was surrounded by an aristocracy (airi aicme, the upper class), whose land and property rights were clearly defined by law and whose main wealth was in cattle. Greater landowners were supported by céilí, or clients.
These and the various other grades of society described by legal writers, worked the land and tended the cattle. Individual families were the real units of society and collectively exercised powers of ownership over their farms and territory. At law the family (fine) did not merely act corporately but was, by one of the oldest customs, held responsible for the observance of the law by its kindred, serfs, and slaves.