Mac Cárthaigh, Diarmaid mac Sheáin Bhuí (c.1640–1705), poet, was son of Seán Buí Mac Cárthaigh, about whom nothing is known, and brother of Donnchadh (Donough) Mac Cárthaigh who was catholic bishop of Cork and Cloyne (1713–26) and was himself the author of verse in both Irish and Latin. The elegies composed for Diarmaid Mac Cárthaigh indicate that he enjoyed a high reputation for learning among his fellow poets and this, together with the fact that his brother studied for the priesthood in France, is suggestive of a prosperous family background. Diarmaid Mac Cárthaigh's writings indicate that he had close links with, and is likely to have been a dependent of, the Muskerry MacCarthys, one of whose principal seats was in the village of Blarney, where the poet appears to have resided throughout his life.
Mac Cárthaigh's earliest datable composition is a lament (‘Och mo threighid is tinn do chéas me’) for Donough MacCarthy (Donnchadh an Chúil Mac Cárthaigh), Lord Clancarty (qv), and his eldest son Cormac, who both died in 1665. The Clancarty title passed to Ceallachán (Callaghan), the second son of Donnchadh an Chúil, and the birth of his heir, Donough, in 1669 was marked by Diarmaid Mac Cárthaigh with a poem (‘D'fheartaibh an Ghrásaigh tharla beo san gcrois’) that predicted the infant would be the future liberator of Ireland. Mac Cárthaigh's best-known composition is a poem (‘Céad buí le Dia i ndiaidh gach anaithe’) in caoineadh metre that celebrated the appointment of Richard Talbot (qv), earl of Tyrconnell, as lord deputy in 1687 and rejoiced at the gaelicisation of the Irish army that had already taken place, noting that sentries now used the challenge ‘Cé súd ann?’ rather than ‘Who is there?’ This work prompted a response in similar vein from Dáibhí Ó Bruadair (qv) in Co. Limerick. If Mac Cárthaigh composed any poems during the Williamite war they have not survived and his next datable composition is an elegy (‘A Shaerbhreathaigh éachtaigh mo bhrón tú’) of more than 300 lines for Justin MacCarthy (qv), Lord Mountcashel, who died in France in 1694. Mountcashel, an exiled Jacobite in the French service, was third son of Donnchadh an Chúil Mac Cárthaigh and is praised in the elegy as ‘phoenix na hÉireann is posta na Mumhan’ (‘Ireland's phoenix and Munster's support’). Diarmaid Mac Cárthaigh also deplored the imprisonment of John Baptist Sleyne, the elderly catholic bishop of Cork and Cloyne, in a poem beginning ‘An méara is an méid sin ag bagairt ar Eoin’, written in the period between the bishop's arrest in 1698 and his transportation from Ireland in early 1703.
Mac Cárthaigh's last datable composition, a lament for his horse (‘Caoinfidh mise m'Fhalartha’), was composed about 1702 and is a significant source of biographical information. The poet's comment that he would have to travel on foot in future since those who would once have provided him with a new mount had gone away – a reference to the attainder and exile of the Muskerry MacCarthys after the revolution – indicates that he was living in straitened circumstances and had lost whatever patronage he had formerly enjoyed. The number of replies that this work elicited from poets such as Fr Conchobhar Ó Briain, Liam Mac Cairteáin (qv), and Éamonn de Bhál (qv), establishes that the literary circle known as the Blarney court of poetry was already in existence; indeed, one of the replies was a poem by Seán Mac Cormaic who styled himself ‘registrar na cúirte’. It may not be coincidental that the sessions of this ‘court’ were held at Blarney, where Diarmaid Mac Cárthaigh lived, and it has been suggested that both Uilliam Mac Cairteáin an Dúna and Éamonn de Bhál were past pupils of a school that he ran in the village.
It is not known if Mac Cárthaigh married or had any children, but he may well have done so as his brother Donnchadh mentioned four nephews and three nieces in his will of 1725, and another nephew of the bishop was a clerical student at Paris in 1724. Diarmaid Mac Cárthaigh died in February 1705 and the laments composed for him include one in Irish by Eoghan Ó Caoimh (qv) and another in Latin by Fr Conchobhar Mac Cairteáin, parish priest of Glanmire.
More information on this entry is available at the National Database of Irish-language biographies (Ainm.ie).