Nisi Mac Niata (or Nissi Mac Niatach, fl. 560 AD) lived in 6th century Gaelic Ireland. Nothing is known of his life, but his death left a legacy for a millennium. Namely, the Túath where he died was renamed in his honour, and his brother Saint CaillÃÂn obtained a substantial honour price in compensation under Brehon Law, securing a revenue stream for the famous monastery of Fenagh.
Nisi (pronounced Nishy) was born in 6th century Gaelic Ireland, the son of and brother of Saint CaillÃÂn, the patron saint of Fenagh. He belonged to the tribe of Conmaicne-Rein who lived in present-day South Leitrim and West Longford. He was probably a noble or a priest, and close associate of his sibling CaillÃÂn. Little else is known of his life.
His death is described in both prose and rhyme by the ancient along the following lines. Sometime in the 5th or 6th century, Nisi and CaillÃÂn journeyed from Ard-Carna Monastery in Roscommon eastwards towards Cora Droma Rúisc crossing the river Shannon to ("the plain of Cellachan"), staying overnight at a place named the Bennachan, in the home of Cellachan, who was not of the Conmaicne tribe. Next morning for some unknown reason, Nisi was killed unlawfully by Cellachan who then had to pay Nisi's brother a substantial "body fine" and honour price in compensation. Nisi was interred at Fenagh.
For the following millennium, the locality where he died was known as ("the plain of Nisi") in his honour. Nisi's "honour price" became the perpetual claim by the monastic settlement at Fenagh to patronage from Moynish nobles.
<blockquote> From Cellachan the active,<br /> The proud plain had been named;<br /> Magh-Nissi, manifest famous,<br /> Is its name from that time down.<br /> Their land and their tributes,<br /> Caillin got for the deed. </blockquote>
The name of Nisi was forgotten when Gaelic Ireland collapsed in the 17th century. Irish nobles had their estates confiscated in the plantations of Leitrim. The English incorporated Moynish into the barony of Leitrim and Cromwellian forces plundered Moynish in 1652. Though forgotten today, the place name of Moynish is preserved by the Irish annals and English Fiants.
The mythical pedigree of Nisi Mac Niata is as follows: