The description of the monastic church at Kildare in Cogitosus's Latin life of St Brigit has given rise not only to several reconstructions but also to the suggestion that the described church is a literary conceit rather than a lost reality. Based on a close reading of Cogitosus's text, this paper will offer a new reconstruction of this church as a historical reality, exploring its anomalies within the context of contemporaneous Irish ecclesiastical architecture, and suggesting that these anomalies demonstrate the use of imitatio Romae as a stratagem of seventhcentury ecclesiastical politics.

Cogitosus's Vitae Sanctae Brigidae is preserved in numerous manuscripts; but its publication history, first documented by Mario Esposito ([1912] 1988, 307–8), is of primary historiographic importance here since study of the church has relied on printed versions of the text. The first printed edition, an abridged version published before 1480 by Bonino Mombrizio in his Sanctuarium seu Vitae Sanctorum ([1910] 1978), does not include the chapter on the church at Kildare. The first complete edition, Heinrich Canisius's Antiquae Lectiones (1604, 623–41), was based on an anomalous Eichstätt manuscript, now lost (Esposito [1912] 1988, 308). Canisius's edition was used by Thomas Messingham in his Florilegium insulae sanctorum seu vitae et acta sanctorum Hiberniae (1624), and revised by Jacques Basnage in his Thesaurus monumentorum ecclesiasticorum et historicorum (1725); Basnage in turn was transmitted by Migne (1878) in the Patriologia Latina (PL), thereby gaining canonical status. John Colgan (1997) produced a somewhat better text in his Acta Sanctorum Hiberniae: Trias Thaumaturga in 1647. The most studiously comparative and reliable early edition, produced in 1658 in the Bollandists’ Acta sanctorum Februarii (1863, vol. 1, 135–41), has not yet been superseded; a new critical edition is anticipated from Sean Connolly and Jean-Michel Picard, who published a preliminary translation in 1987.

Cogitosus was probably a religious at the monastery of Kildare. His vita of Brigit is usually dated in the third quarter of the seventh century, given Muirchú’s reference to Cogitosus as pater in the Vita Patricii, which is dated about 680 and certainly before 700 (Esposito [1912] 1988, 321–4; Kenney 1993, 359; Sharpe 1982, 86–7; MacCone 1982, 108; Connolly 1987, 5).