 In the period spent in Ostend he commissioned the writing of two manuscripts, a collection of Fenian Lays, "Duanaire Finn", and a collection of bardic poetry, "The Book of O'Connor Donn".The collection of Lays in "Duanaire Finn", written by the scribe and soldier Aodh Ó Dochartaigh in 1627, was published by Dr Eoin Mac Néill and Gerard Murphy in three volumes between 1908 and 1953.Both books were bequeathed by Mac Domhnail to the Irish College in Leuven.