Rarely did early authors or historians sign their names to works, but Best believed he could definitively state the identity of M as as Máel Muire mac Céilechair meic Cuinn na mBocht. Máel Muire (Old Irish: "Servant of Mary") was a cleric at the monastery of Clonmacnoise, part of a family of clerics that had been connected to Clonmacnoise for centuries.
How was the identification made? Well, a marginal note written much later than the Lebor claims that Máel Muire was the person who wrote and compiled this book from diverse books. But notes that are added are not always reliable. In this case, however, there is also the evidence of the probationes pennae (Latin for "pen tests"; singular probatio pennae). When cutting a new quill pen, the scribe would test the point by scribbling something, maybe in the margin, maybe on a scrap of blotting paper. (Paper/parchment wasn't cheap, so it would be saved for use, perhaps as a binding.) There are two probationes pennae at Clonmacnoise where Máel Muire wrote his name, and Best said the penmanship in the autographical pen test was the same as the writer M in the Lebor.
One of the benefits of this identification is that, since we know Máel Muire's death, we know a date prior to which the Lebor was being written. The Annála na gCeithre Máistrí (Middle Irish: "Annals of the Four Masters"), covering Irish history from Noah's Deluge to 1616CE, claim Máel Muire was killed by Vikings at Clonmacnoise in 1106.
Poor Clonmacnoise! It suffered extensively, with attacks from the Irish, the Vikings, and the Normans. Let's look at its history tomorrow.
