Leabhar Glinne Dá Locha
The Book of Glendalough
Rawlinson MS B 502
Oxford, Bodleian Library
c. AD 1130.

Manuscript on vellum and paper, 166 pages composed between 1100 and 1130 AD, at Glendalough, County Wicklow.

When The Book of Leinster was catalogued at Trinity College, it was mistakenly called "The Book of Glendalough, sometimes called the Book of Leinster," as based on an inscription made in 1743.^[1] This caused much confusion, leading to the idea that there are two Books of Leinster. This is not the case. The Book we think of as the Book of Leinster is, in Gaelic, called Lebhar Na Núachongbála. This was not the original Book, nor is the Book of Glendalough--nor are these the same book. Instead, there was a first Book of Leinster--now either lost or existing under a different name; the Book of Glendalough (our present subject); and what we now call The Book of Leinster, which is properly called Lebhar Na Núachongbála. Some scholars argue that neither of these books are the Book of Leinster, nor are they Glinne Dá Locha or Núachongbála, but other manuscripts, the originals being lost. Needless to say, there is much confusion over the identities of these manuscripts.^[2] Even today, books published by Oxford confuse the two manuscripts (see The Oxford Dictionary of Celtic Mythology for this).

The book itself contains many genealogies, copied from sources older (which does not mean more reliable) than the book. It also contains various tracts, such as "The Wonders of Ireland"--similar to the mirabila at the end of Historia Brittonum--miracle stories of the saints, and short historical annecdotes.

In 1909, Kuno Meyer made a fascimilie version of the vellum pages, published by the University of Oxford Press.

The Book of Glendalough now resides at the Bodleian Library, Oxford.

The genealogies can be found here.

NOTES
1. The Book of Glendalough. http://www.isos.dcu.ie/tcd/Intro_Book/pagei.htm
2. http://listserv.heanet.ie/cgi-bin/gaelic-l?list=old-irish-l&log=log0202&msg=49477

OTHER SOURCES
MS-OMIT: http://titus.uni-frankfurt.de/texte/ms-omit/manuscri.htm