The book is devoted to the system of values of Celtic military aristocracy and the place of the royal druzhina in the early medieval Irish society. The work consecutively considers the peculiarities of the Irish epic, internal mechanisms of the druzhiny institution functioning, as well as the place of the military aristocracy in the system of social relations. The geography of the study is limited exclusively to Ireland. This is due to the fact that there was no influence of Rome and Germanic tribes, thanks to which the whole structure of the ancient Celtic world was preserved. The chronological framework of the study is defined by the I-8th centuries - this is the time of formation and formation of the epic tradition. The author draws attention to the fact that the institution of military aristocracy was not static - it was a constantly evolving organism. Accordingly, its relations with other institutions - royalty, priesthood and community - were also constantly changing, passing from assistance to opposition.