Gill, Michael Henry (1794?–1879), printer, was born c.1794, son of Henry Gill (d. 1797?) and his wife Catherine (née O'Neill). Henry, whose family probably originated in King's Co., was a woollen draper in Skinners’ Row, Dublin, and in the early 1790s was a member of the Dublin Society of United Irishmen. At 19, Michael Henry Gill was apprenticed in the printing trade to the firm of Graisberry & Campbell which had the lease of Dublin University Press with premises at TCD. He became manager of the firm (1827), then a partner (1833) and eventually acquired full ownership of the firm (1837). As early as 1833 books issued from Dublin University Press bear the imprint M. H. Gill. He printed for two other firms, William Curry, Junior & Co. and James McGlashan. Later he purchased McGlashan's stock, copyrights and premises (1 January 1856), thus founding the firm of McGlashan & Gill of 50 Upper Sackville St., which finally became M. H. Gill & Son (1876). The firm printed the seven volumes of John O'Donovan's (qv) edition of the Annals of the Four Masters (1848–51), for which it used Gaelic type designed by George Petrie (qv). Gill was printer and publisher of the Jesuit-edited Irish Monthly from its inception in 1873. For some years he was described as ‘printer to the Royal Irish Academy’. Not until 1875 did he sever his connection with Dublin University Press. Michael Henry Gill died 20 March 1879 at his residence, 50 Upper Sackville St., aged about 85 and was buried at Glasnevin. He married Mary Catherine Hart (1812–60).
His eldest and only surviving son, Henry Joseph Gill (1836–1903), after an education at Castleknock and TCD (BA, 1857), managed for many years all departments of the business and turned the firm into the premier catholic publishing house in Ireland. He was the inventor of the Gill hot-rolling machine (patented, 1874), a founder member of and printer to the Society for the Preservation of the Irish Language (from 1876) and a translator from French, German, Italian and – most notably El Cid (1895) – from Spanish. He was a member of Dublin city council (from 1877) and home-rule MP for County Westmeath (1880–83) and Limerick city (1885–8). Under his management M. H. Gill & Son published catholic prayer books and sermons, works of fiction and non-fiction, school-books, and two Irish primers: College Irish grammar by Ulick Bourke (qv) and Lessons in Irish by Eugene O'Growney (qv). Henry Joseph Gill died 29 October 1903, aged 66, at his home, Roebuck House, Clonskeagh, Co. Dublin. He married (1870) Mary Julia, daughter of James Keating. She died on 4 May 1905.
Their eldest son, Michael Joseph Gill (1871?–1913), was educated at Clongowes and UCD (both managed by Jesuits), graduating in the RUI (1893). He had already entered the family firm in 1888 and after his father's death was managing director until his own premature death in Rome on 27 May 1913. He too was an innovator. Under his management the firm published the pamphlets of the Catholic Truth Society of Ireland (founded 1899) and a lay monthly, the Catholic Bulletin (founded 1911), as well as branching out into the sale of ecclesiastical and devotional goods. Like his father he had literary and political interests – he acted as secretary and treasurer of the National Literary Society (1893–7), was on the council of SPIL and contributed articles to the publications issued by M. H. Gill & Son. He died unmarried. Another son, Henry Vincent Gill (1872–1945), was a Jesuit priest; he served as a chaplain throughout the first world war (during which he kept a diary), returned to Dublin and pursued a career as a scientist, writer and teacher. The youngest son, Richard Aloysius Gill (1881?–1923), succeeded as head of the firm, made administrative and technical improvements and was succeeded eventually, after a period of management by Patrick T. Keohane (d. 1939), the company secretary since 1903, by his son William (1908–81). In 1965 the firm (since 1903 M. H. Gill & Son Ltd) ceased printing but continued publishing and bookselling; in 1968 a partnership was formed with Macmillan's (as Gill & Macmillan Ltd) to conduct its publishing business; in 1979 the retail business ceased. Gill & Macmillan's managing director until 2006 was Michael Gill, great-great-grandson of Michael Henry Gill.