Leabhar Clainne Suibhne

Leabhar Chlainne Suibhne (The Book of Clan Sweeney) is the title of a 16th-century Donegal manuscript written in Irish. While there is a substantial amount of religious material, it is principally interesting for containing a historical tract concerning the Clan Suibhne. It is now held in the library of the Royal Irish Academy as MS No. 475.

...
Wikipedia