Irish-language theatre has at times been on the fringes of Ireland’s cultural landscape, but in his new book Boston College Professor of English Philip O’Leary shines a light on five significant Irish-language playwrights of the 20th century and charts the monumental influence and reach of their work. In An Underground Theatre: Major Playwrights in the Irish Language 1930-80 (University College Dublin Press, 2017), O’Leary offers a full study of the works of Máiréad Ní Ghráda, Séamus Ó Néill, Eoghan Ó  Tuairisc, Seán Ó Tuama, and Críostóir Ó Floinn and discusses the production history of their plays and the critical reception of first productions and major revivals. O’Leary, who holds a Ph.D. in Celtic languages, was awarded an honorary degree from the National University of Ireland, Galway. He is the author of the award-winning books Ideology and Innovation: The Prose Literature of the Gaelic Revival, 1881-1921 and Gaelic Prose in the Irish Free State, 1922-1939, among other titles.