''TheIs principalamhlaidh compilergurbh andé scribepríomhtheaglamaí agus scriobhneoir an wasleabhair probablyná [[Áed Ua Crimthainn]],<ref>Best, ''The Book of Leinster'', vol 1, p. xv.</ref><ref name=Hellmuth>Hellmuth, "''Lebor Laignech''", ppll. 1125-6.</ref> whoab wasna abbotmainistreach of[[Tír theDhá monasteryGhlas|Thír ofDhá Ghlas]]<ref>[https://www.logainm.ie/2221.aspx Tír-Dá-GlasonDhá theGhlas] Shannon,ar nowlogainm.ie</ref> [[Terryglass]]i (g[[CountyContae Tipperary Thiobraid Árainn]]).<ref name=Hellmuth /> Áed'sIs signatureféidir cansíniú beAodha a readléamh onar f. 32r (p. 313): ''Aed mac meic Crimthaind ro scrib in leborso 7 ra thinoil a llebraib imdaib'' ("Scríobh ÁedAodh Uí ChrimthainnChrimhthainn an leabhar seo agus andthionóil collected[sé ité] fromó manymhórán booksleabhar"). In a letter copied by a later hand into a bottom margin (lch. 288), the bishop of Kildare, Finn mac Gormáin (d. 1160), addresses him as a man of learning (''fer léiginn'') of the high-king of [[Leth Moga]]; the coarb (''comarbu'' lit. 'successor') of [[Columba of Terryglass|Colum mac Crimthainn]]; and the chief scholar (''prímsenchaid'') of Leinster.''
In a letter copied by a later hand into a bottom margin (lch. 288), the bishop of Kildare, Finn mac Gormáin (d. 1160), addresses him as a man of learning (''fer léiginn'') of the high-king of [[Leth Moga]]; the comharba (''coamhru'') [[Colum mac Crimthainn]]; agus príomhscoláire (''prímsenchaid'') Laighean.
''An alternative theory was that by [[Eugene O'Curry]], who suggested that Finn mac Gormáin transcribed or compiled the Book of Leinster for Áed;<ref name=Hellmuth /> and/or that the manuscript may have been commissioned by [[Diarmait Mac Murchada]] (d. 1171), king of Leinster, who had a dún i n[[Dún Másc]], in aice leis An Nuachongbáil.''