Published in two volumes in 1862 and 1867, it remains a basic reference book for anyone interested in the history of Christianity in Ireland, because it relied for information on three sources of information no longer available to modern historians; folklore and folk memories from people in the 1850s and 1860s that covered such time periods as the Penal Laws and the Irish Potato Famine; information from the Meath diocese's own archives, which were subsequently lost during a move of the Bishop's cathedral seat from Navan to Mullingar; and information from Ireland's Public Records Office, all of whose contents were destroyed when the IRA blew up the PRO in 1922.