Together the four treasures form the subject of at least three Middle Irish texts: In the 17th century, Geoffrey Keating drew on a version of the former for his Foras Feasa ar Éirinn.
[2] The first recension of Lebor Gabála describes the Tuatha Dé Danann as having resided in "the northern islands of the world", where they were instructed in the magic arts, before finally moving in dark clouds to Connaught in Ireland.
CMT and LG tell that there were four cities located on the northern islands of the world (i n-insib tūascertachaib in domain), called Falias, Gorias, Findias and Murias.
[4] "The Four Jewels" also refers to the cities, but appears to locate them at Lochlann and contends that the Tuatha Dé crossed the seas in their fleet rather than in a mist.
[4] When the Tuatha Dé migrated to Ireland, they are said to have brought four magical instruments from these cities: A. C. L. Brown and R. S. Loomis equate Lug's spear with the Lúin of Celtchar, which in Togail Bruidne Dá Derga is said to have been discovered in the Battle of Mag Tuired.