Cathal (d. 742), son of Finguine and king of Munster, was a member of the Éoganacht Glendamnach dynasty (Rawl. B. 502, 148a 44, b1; LL, 320c 54). His father Finguine was a son of Cathal Cú cen Máthair (qv), but there is no record of his mother or of any siblings. While later tradition associates him with the legendary queen Mór Muman, there is more reason to accept as historical the ‘Banshenchas’ (lore of women) assertion that he married Caillech (d. 731) daughter of Dúnchad Ard, an Uí Meic Brócc dynast of the south-east Munster marches. Cathal had a daughter, Tualaith, and a son (or grandson), Artrí (qv). The regnal list ‘De rígaib Muman iar Cretim’ claims a reign of twenty-nine years for Cathal as king of Munster, implying that he succeeded to the provincial kingship in 713, after the death of Cormac son of Ailill of Éoganacht Chaisil. It would appear, however, that there was difficulty in establishing effective political control of the province at this time. In 715 the Leinster king Murchad (qv) (d. 727) son of Bran was able to march on Caisel. The reality, in all likelihood, was that Cathal enjoyed only local or regional power in these early years, attaining a meaningful overkingship of Munster only in 721, after the death of Etarscél son of Máel-umai of Éoganacht Áine. Cathal features last in the list of ‘future’ kings according to the foundation story of Caisel, prompting the suggestion that the list is in fact an eighth-century product.
From the time of his attainment of provincial overkingship, it would appear that Cathal pursued a consistent policy of seeking to restrict the Uí Néill sphere of influence to Leth Cuinn (the northern half of Ireland). Towards this end, he joined forces with the king of Leinster, Murchad son of Bran, and laid waste the plain of Brega, which extended across east Co. Meath and north Co. Dublin (721). There may be some substance to the claim in the admittedly partisan Annals of Inisfallen that, after these actions, the Uí Néill king Fergal (qv) son of Máel-dúin submitted to Cathal; certainly, a propaganda verse of late (probably 11th-cent.) date includes Cathal as one of five Munster kings who ‘ruled Ireland’. Cathal secured his alliance with the Uí Dúnlainge dynasty of Leinster by means of a judicious political marriage: his daughter Tualaith became the wife of Dúnchad (qv) son of Murchad (d. 728). It would seem that the internecine conflict within Uí Dúnlainge, which followed the death of Murchad son of Bran (727), upset Cathal's plans to play kingmaker in Leinster. In spite of support from his father-in-law and the king of Osraige, Dúnchad son of Murchad was defeated and slain (728) by his brother Fáelán (qv), who assumed the kingship of Leinster and married Tualaith. Cathal's efforts to secure dominance over Leth Moga (the southern half of Ireland) now focused on southern Leinster, but his offensive against the Uí Chennselaig dynasty (732) met with a reverse. Three years later he attacked again; according to the Annals of Ulster he was defeated by the Leinstermen at Belach Éile (probably in Co. Carlow near the River Burren), and his ally the king of Osraige was slain, but the Annals of Inisfallen insist that the Munster king was in fact the victor.
The extent to which Cathal posed a threat to the Uí Néill political order has been much discussed. If it is accepted that an Annals of Ulster entry (733) refers to him and not to a like-named Síl nÁedo Sláine dynast (the absence of a patronymic in the annal seems to suggest a well-known individual), it is on record that he made an incursion deep into Mide. Although beaten away from the assembly site of Tailtiu, he managed to defeat an Uí Néill dynast at Tlachtga (the Hill of Ward). There was no precedent for such a move on the part of a Munster king, but Cathal had earlier raided Brega and apparently had ambitions to extend his influence beyond Leth Moga. He is styled Ardrí Temrach (high-king of Tara) in the poem ‘Teist Cathail meic Finguine’, while there is an allusion to the Feis Temro (feast of Tara) in the law tract ‘Bretha Nemed Toísech’ (probably a Munster product dating to 721–42). If these are to be viewed as Munster propaganda, it must be noted that the Uí Néill regnal poem ‘Baile Chuinn’ (apparently reworked in the 720s) makes mention of fer fingalach (‘a kin-slaying man’), a descendant of Corc (an Éoganacht dynast) who is ‘overlord of Munster of great princes in Tara’ – a pointed reference to Cathal son of Finguine.
From the mid 730s, however, Cathal found his ambitions stymied by the emergence of a strong Cenél nÉogain candidate, Áed Allán (qv) son of Fergal, as overking of the Uí Néill. In 737 a rígdál (royal meeting) took place between the two at Terryglass (Co. Tipperary). Quite possibly a non-agression pact was agreed and was afterwards upheld throughout Ireland as the Law of Patrick (qv); it can be inferred that Cathal consented to acknowledge the ecclesiastical authority of Armagh in Munster. The annalistic record for the following year is confused and it is not clear whether Cathal's taking of the hostages of Leinster preceded Áed Allán's invasion of the province – and so, perhaps, provoked it – or followed the invasion, thus representing an attempt to reassert his authority within Leth Moga. In either case, it seems clear that Cathal's claim to supremacy in southern Ireland was under threat from this powerful king of Tara. Cathal died in 742 and, according to a verse of later date included in the Annals of Inisfallen, was buried in Imlech Iubair (Emly, Co. Tipperary). Clearly, his reign was viewed as a milestone by later generations; quite apart from the already-mentioned claim of the five Munster kings who ‘ruled Ireland’, Cathal is a prominent figure in Middle Irish literature. He features in the saga ‘Cath Almaine’ (the battle of Allen), and in the satire ‘Aisling Meic Conglinne’ he is the king from whom the hero Mac Conglinne expels a demon of gluttony. The immediate succession to Cathal in the overkingship of Munster is unclear: it would seem that he was followed by ephemeral kings from other Éoganacht lineages. Artrí (d. 821) – probably a grandson of Cathal – succeeded in regaining the kingship in 796; from him descended the later Éoganacht Glendamnach kings.