Since we have no Roman accounts of the form of government or state of society in ancient Erin, we must only depend on the Bards and Story-tellers, so far as their statements are credible and agree with each other. On certain main points they do agree, and these are the points which it seems reasonable for us to take on their authority.
As even brothers born of the same mother, coming suddenly into possession of a prize, will struggle to see who can get the largest share, so we find in those first ages a constant succession of armed struggles for power. The petty Princes who divided the Island between them were called Righ, a word which answers to the Latin Rex and French Roi; and the chief king or monarch was called Ard-Righ, or High-King. The eldest nephew, or son of the king, was the usual heir of power, and was called the Tanist, or successor; although any of the family of the Prince, his brothers, cousins, or other kinsmen, might be chosen Tanist, by election of the people over whom he was to rule. One certain cause of exclusion was personal deformity; for if a Prince was born lame or a hunchback, or if he lost a limb by accident, he was declared unfit to govern. Even after succession, any serious accident entailed deposition, though we find the names of several Princes who managed to evade or escape this singular penalty. It will be observed besides of the Tanist, that the habit of appointing him seems to have been less a law than a custom; that it was not universal in all the Provinces; that in some tribes the succession alternated between a double line of Princes; and that sometimes when the reigning Prince obtained the nomination of a Tanist, to please himself, the choice was set aside by the public voice of the clansmen. The successor to the Ard-Righ, or Monarch, instead of being simply called Tanist, had the more sounding title of Roydamna, or King-successor.
The chief offices about the Kings, in the first ages, were all filled by the Druids, or Pagan Priests; the Brehons, or Judges, were usually Druids, as were also the Bards, the historians of their patrons. Then came the Physicians; the Chiefs who paid tribute or received annual gifts from the Sovereigns, or Princes; the royal stewards; and the military leaders or Champions, who, like the knights of the middle ages, held their lands and their rank at court, by the tenure of the sword. Like the feudal Dukes of Prance, and Barons of England, these military nobles often proved too powerful for their nominal patrons, and made them experience all the uncertainty of reciprocal dependence. The Champions play an important part in all the early legends. Wherever there is trouble you are sure to find them. Their most celebrated divisions were the warriors of the Red Branch - that is to say, the Militia of Ulster; the Fiann, or Militia of Leinster, sometimes the royal guard of Tara, at others in exile and disgrace; the Clan-Degaid of Munster, and the Fiann of Connaught. The last force was largely recruited from the Belgic race who had been squeezed into that western province, by their Milesian conquerors, pretty much as Cromwell endeavoured to force the Milesian Irish into it, many hundred years afterwards. Each of these bands had its special heroes; its Godfreys and Orlandos celebrated in song; the most famous name in Ulster was Cuchullin: so called from cu, a hound, or watch-dog, and Ullin, the ancient name of his province. He lived at the dawn of the Christian era. Of equal fame was Finn, the father of Ossian, and the Fingal of modern fiction, who flourished in the latter half of the second century. Gall, son of Morna, the hero of Connaught (one of the few distinguished men of Belgic origin whom we hear of through the Milesian bards), flourished a generation earlier than Finn, and might fairly compete with him in celebrity, if he had only had an Ossian to sing his praises.