The Book of Leinster (Irish Lebor Laignech), is a medieval Irish manuscript compiled ca. 1160 and now kept in Trinity College, Dublin, under the shelfmark MS H 2.18 (cat. 1339). It was formerly known as the Lebor na Nuachongbála "Book of Nuachongbáil", a monastic site known today as Oughaval. Some fragments of the book, such as the Martyrology of Tallaght, are now in the collection of University College, Dublin
Nothing certain is known of the manuscript's whereabouts in the next century or so after its completion, but in the 14th century, it came to light at Oughaval. It may have been kept in the vicarage in the intervening years. The Book of Leinster owes its present name to John O'Donovan (d. 1861), who coined it on account of the strong associations of its textual contents with the province of Leinster, and to Robert Atkinson, who adopted it when he published the lithographic facsimile edition.
However, it is now commonly accepted that the manuscript was originally known as the Lebor na Nuachongbála, that is the "Book of Noghoval", now Oughaval (Co. Laois), near Stradbally. This was established by R.I. Best, who observed that several short passages from the Book of Leinster are cited in an early 17th-century manuscript written by Sir James Ware (d. 1666), found today under the shelfmark London, British Library, Add. MS 4821. These extracts are attributed to the "Book of Noghoval" and were written at a time when Ware stayed at Ballina (Ballyna, Co. Kildare), enjoying the hospitality of Rory O'Moore[disambiguation needed]. His family, the O'Moores (Ó Mhorda), had been lords of Noghoval since the early 15th century if not earlier, and it was probably with their help that he obtained access to the manuscript. The case for identification with the manuscript now known as the Book of Leinster is suggested by the connection of Rory's family to the Uí Chrimthainn, coarbs of Terryglass: his grandfather had a mortgage on Clonenagh, the home of Uí Chrimthainn. Best's suggestion is corroborated by evidence from Dublin, Royal Irish Academy MS B. iv. 2, also of the early 17th century. As Rudolf Thurneysen noted, the scribe copied several texts from the Book of Leinster, identifying his source as the "Leabhar na h-Uachongbála", presumably for Leabhar na Nuachongbála ("Book of Noughaval"). Third, in the 14th century, the Book of Leinster was located at Stradbally (Co. Laois), the place of a monastery known originally as Nuachongbáil "of the new settlement" (Noughaval) and later as Oughaval.
The Book of Ballymote
The Book of Lecan
The (Great) Book of Lecan (Irish: Leabhar (Mór) Leacain) (RIA, MS 23 P 2) is a medieval Irish manuscript written between 1397 and 1418. It is in the possession of the Royal Irish Academy. Leabhar Mór Leacain is written in Middle Irish and was created by Ádhamh Ó Cuirnín for Giolla Íosa Mór Mac Fhirbhisigh. The material within was transcribed from the Book of Leinster, latter copies of the Book of Invasions, the dinsenchas, the banshenchas and the Book of Rights. At one stage it was owned by James Ussher. James II of England then deposited it at the Irish College, Paris. In 1787, the Chevalier O'Reilly returned it to Ireland; where it was at one stage in the possession of Charles Vallancey. He passed it on to the Royal Irish Academy. There were originally 30 folios; the first nine were apparently lost in 1724. Unfortunately these contained a large section devoted to the pedigrees and history of the Norse and Norse-Gaelic families of Ireland, which are nowhere else preserved. The pages are unfortunately covered in a greasy substance which makes them transparent and reduces their legibility.
Note: A portion of the article is an extract from Yvonne Vetjens and the other party that includes all three books (text) and photographs, is mine.