Croinic nó leabhar oiris is ea '''Annála Tiarnaigh''' (giorrúchán '''AT'''), is dócha tosaithe i g[[Cluain Mhic Nóis]] i n[[Éirinn]]. Scríobhadh iad as [[Laidin]], agus [[Sean-Ghaeilge|Sean-]] agus [[Meán-Ghaeilge Irish]].
''ManyIs ofé the[[Rawlinson pre-historicB entries502]], comesaothar fromden the 12th-century12ú MShaois, [[Rawlinsonfoinse Bgo 502]]leor iontráil réamhstairiúil.<ref name=Hughes>Hughes, ''Early Christian Ireland: Introduction to the Sources'', ll. 99-162.</ref> However,Is theí realtábhacht importancena ofhannála theámh chroniclená isna for the periodtréimhsí 489-766, 973–1003 andagus 1018–1178.<ref name=Hughes /> TheseCaomhnaítear threetrí fragmentsbhlúirín survivei fromlámhscríbhinn theden 14th-century14ú MShaois, [[Rawlinson B 488]].<ref name=Hughes /> TheTá coveragena ofhiontráil thedosna periodblianta 766 togo 973 is lostcaillte, butach isceaptar thoughtgo tobhfuil surviveachoimre indóibh abbreviatedle formfáil in thesa ''[[Chronicon Scotorum|Chronicon Scottorum]]'' (giorr. '''CT''').<ref name=Hughes /> ''The latter is defective for the period 718 to 804, but as much of its content is derived from the hypothetical ''[[The Chronicle of Ireland|Chronicle of Ireland]]'' (itself partly derived from the ''[[Iona Chronicle]]''), of which the ''[[Annála Uladh]]'' (giorr. '''AU''') and ''[[Annála Inis Faithlinn]]'' (giorr. '''AIF''') are also derived, we have some idea of what the entries contained.<ref name=Hughes /> Molann [[Kathleen Hughes (historian)|Kathleen Hughes]] postulatesgur thatdiverged AU andagus AT diverged from theó ''Chronicle of Ireland'' sometime before the year 913.<ref name=Hughes />
''The chronicle owesTá itsna modernhannála nameainmnithe toas ''[[Tigernach Ua Braín]]'' (d. 1088), [[abb ofChluain Clonmacnoise]]Mhic Nóis, butach thisní doeshionann notsin meanagus thatgurbh heeisean wasan also its authort-údar. AnoteDeir addednóta toámh the entry for 1088, the year of his death, ini Rawlinson B 488 statesdon thatbhliain the1088, textbliain wasa writtenbháis, bygur Tigernachscríobh upTiarnach toan thattéacs point.go dtí Ifan he was not merely the scribe of the original text copied by the 14tht-century scribe, it may mean that he was one of the [[annalist]]s responsible for theam worksin.<ref>Charles-Edwards, "Ua Braín, Tigernach (''d''. 1088)"</ref>
