The Niadh Nask is an order of knighthood invented by one Terence MacCarthy, a native of Belfast who assumed sometime in the early 1980s or late 1970s the style of MacCarthy Mór.
This order's claims to legitimacy, as well as Terence MacCarthy's other claims (descent from the royal house of Eoghanacht, right to the title of prince of Desmond, right to sell various titles and lordships) have been debated extensively on the newsgroup rec.heraldry (they can be retrieved through Google Groups, formerly known as the Deja News archive).
Most if not all sites devoted to the Niadh Nask have disappeared
from the Web following the collapse of Terence MacCarthy's fraud.
The following paragraph is outdated, the links broken, and
the persons named have disassociated themselves from the NN.
The
official web site of the "Terentines" is maintained by
Patrick O'Shea ("lord of Tiraha"). Their publishing house is
run by David Wooten. See also the
page and links by another member, Carl Lindgren.
There is an exchange on Caltrap's Corner between James Algrant and Patrick O'Shea. There is also a report on Terence MacCarthy's pedigree by Sean J. Murphy.
The Chief Herald of Ireland withdrew Terence MacCarthy's recognition as clan chief and courtesy title of MacCarthy Mór in July 1999. That seems to have prompted a number of defections in the ranks of the Terentines. The MacCarthy Mór's replies, once posted on the Web by one of his supporters, have been taken down since the supporter changed his mind in early Oct. 1999. They can still be found on the the MacCarthy clan Web site (as of Oct. 14) but perhaps not for long.
the officers of the Niadh Nask have issued a statement repudiating their former Grand Master. They are now (Oct. 1999) looking for a way to perpetuate their organization.