Mac Cairteáin, Liam (an Dúna) (William MacCartain) (c.1668–1724), scribe and poet, was born in Doon, Co. Cork. Nothing is known of his parents, but it is believed that he was of Ulster origin. A Jacobite, he was a major in Mac Cárthaigh Spáinneach's cavalry regiment that took part in an ambush of Williamite forces at Béal Átha Salainn near Carrignavar, Co. Cork (29 April 1691), and is believed to have fought at the battle of the Boyne. According to a poem he composed in reply to Eoghan Ó Caoimh's (qv) ‘Ar treasradh in Eachdhruim’, he was also present at the battle of Aughrim. After the war he earned his living as a farmer and possibly also as a teacher in Drom Buí in the parish of Carrignavar, Co. Cork. He also owned land in the parish of Whitechapel, Co. Cork.
Approximately thirty of Mac Cairteáin's poetic compositions are extant, including a Jacobite song, ‘A chlanna Gael, fáiscidh bhur lámha le chéile’, which he is said to have composed on his way to the battle of the Boyne, and a poem in reply to Diarmuid mac Sheáin Buí's (qv) lament on the death of his horse, ‘an Fhalartha Ghorm’. On 14 July 1700 he composed a poetical address to Sir James Cotter (qv) (d. 1705), who had assassinated the regicide John Lisle at Lausanne, Switzerland, on 11 August 1664. Mac Cairteáin's poems provided an indication of the true name of the assassin. A false name, ‘Thomas McDonnell’, had been circulated prior to that. He also composed three poems on the exile of John Baptist Sleyne (1639?–1712), catholic bishop of Cork, Cloyne, and Ross, to Portugal in 1703. Two years later (1705) Mac Cairteáin succeeded Diarmuid mac Sheáin Bhuí Mac Cárthaigh as chief poet of the Blarney cúirt éigse (assembly of poets) and remained in the position until his death. As a result he came into contact with other prominent poets and scribes in the area, including Seán na Ráithíneach Ó Murchadha (qv), the local parish priest Fr Conchubhair Mac Cairteáin, Éamonn de Bhál (qv), Eoghan Ó Caoimh, and Diarmuid mac Sheáin Bhuí Mac Cárthaigh. Conchubhair Mac Cairteáin described him as file fiosach focailbhínn agus duine uasal árdfoghlamtha (a knowledgeable sweet-worded poet and highly educated gentleman) (Ó Conchubhair (1982), 18). He acted as sponsor for Eoghan Ó Caoimh on the latter's ordination as a priest and was also a godfather to Ó Caoimh's son Art. A number of poetical contentions arose between the men, however. On one occasion Ó Caoimh believed that Mac Cairteáin had not sufficiently expressed his condolences to him on the death of Art, and composed a poem condemning him.
In addition to composing poetry Mac Cairteáin was also a scribe and may have been employed by Mac Sleighne to provide copies of manuscripts. He is known to have borrowed a number of manuscripts from the bishop, including the one from which he transcribed (1701–2) Geoffrey Keating's (qv) ‘Eochairsgiath an Aifrinn’. The exemplar for ‘Agallamh na Seanórach’, which he copied between 1700 and 1703, may also have belonged to Mac Sleighne. He died in November 1724 and is buried in Whitechapel cemetery, Co. Cork. Seán na Ráithíneach composed a lament in his honour.
Although Mac Cairteáin married, his wife's name is unknown, and it is unclear how many children the couple had. Only the name of one son, Dónall, is known for certain, thanks to two poems composed by Seán na Ráithíneach in his honour. Dónall was also a poet in his own right. Mac Cairteáin may also have had two other sons, Tadhg Mac Cairteáin and Seaghan Buidhe an Dúna, and a daughter. His manuscripts are held in the RIA, the NLI, and the BL.