This work is a systematic analysis and classification of Irish accentual verse-metres. An assessment of previous contributions to the study of Irish verse-practice is followed by a general survey of metrical scholarship, which in turn lays the groundwork for a metrical theory of Irish accentual verse. Space is devoted to a phenemologically-based discussion of the role of rhythm in spoken Irish and its implications for verse-structure. The heard of the work consists of a taxonomical survey of Irish accentual verse-types, in which the principal criterion for inclusion in a given category is the number of stressed syllables in a line. Following chapters deal with stanzaic and supra-stanzaic structure and verse ornament, the musical context of verse, the ways in which musical metre differs from verse metre, and the implications of such differences for a system of versification primarily transmitted through a musical medium.