"Beginning with a manual for learning the Irish language (""Irish for the people"" 1946), Proinsias Mac an Bheatha published two biographies, three historical novels, an autobiography, four collections of essays, two historical studies, and a collection of original poetry, all excepting the manual in Irish. Two of these were published posthumously by his family. The series contains preparatory material for some of the titles, some items of correspondence drafts and faircopies, and reviews or other material adding to the published item. Notably, there are some pamphlets concerning James Connolly, not all used for drafting ""Tart na Córa"" (1963), Mac an Bheatha's biography of Connolly, but collected later."
Mac an Bheatha sporadically collected published items of interest from the press as well as pamphlets. The main themes are the Irish language and its treatment by the government, Irish history, and trade unionism. One stray monograph publication is contained in the series.
Mac an Bheatha's private and business correspondence comprises items mostly concerning his press work and other publications, some items from friends, and from the reading public. There are few drafts for outgoing letters. The main themes are the Irish language and its promotion in Irish society, and Irish history. Among notable correspondents there are Cardinal Ó Fiaich, Róisín Ní Mheara, Muiris Ó Droighneáin, Gabriel Rosenstock, Ciarán Ó Coigligh, Erna Bennett.
Mostly containing items of correspondence sent to George Gilmore, some reflecting Gilmore's political views, and his later activities as public speaker and contributor to the press.
"Full drafts of a published pamphlet (""Labour and the republican movement"" (1966)), a lecture (""Prods, papes and Republicans"" (1980)) by George Gilmore, and brief fragments of plays in the tradition of agitprop."
Having joined this branch of Conradh na Gaeilge at its inception, Mac an Bheatha fulfilled administrational roles in it and to varying degrees dealt with membership, general meetings, and the correspondence with the branch.
Mac an Bheatha was one of the founding members of Glúin na Bua, a movement founded along similar lines to Conradh na Gaeilge's Craobh na hAiséirí, but independent from it. It was dedicated to spreading use of the Irish language by virtue of public meetings, organising youth groups and Gaelic events, publishing pamphlets and disseminating information in general. Having overseen its first constitution, he served as director of the Glúin for over two decades, and dealt with aspects such as membership, accounts, and correspondence, reflected in the material here. The impetus of the movement was greatly diminished even by the 1950s, and it had ceased to exist by the early 1980s.
"""Inniu"" was founded and maintained by the Irish language movement Glúin na Bua on the instigation of Ciarán ó Nualláin, its later long-term editor (1943-1971). As director of Glúin na Bua, Proinsias Mac an Bheatha was involved with the first issues of the paper, and collected items illustrating aspects of its administration, content, and general history. The series contains some administrational material (correspondence mostly), communications from readers, press cuttings, and issues of ""Inniu""."