Nelson
Nelson—The origin of this name needs a lengthy note to make it clear. In the Isle of Man the name Nelson was written early Mac Neill, and during the various stages of anglicisation it arrives at its present form, the name being common on the island, the changes reading "Neillson," "Nealson," "Neleson," and finally "Nelson." One, Nial, was King of Man in 914, according to the Egilla Saga, and, in 1430 A. D., the name was written Nealson in the Southern part of the Island, and Nelsson in 1511. Other anglicised forms the name has taken are Kneale and Neild. In Ulster in the earlier part of the 19th century Neilson was the common form, and towards the end of that century that form had given place to Nelson.
The origin of Niall itself is of great antiquity in Irish history, and it is to the Nialls of Ulster we must trace the origin of the name.
The Norsemen adopted Niall under the form of Njal, and Njal is the prominent figure in the "Saga of Burnt Njal," which deals with the early Irish settlers in Iceland.
Some Scottish bearers of the name Neilson claim for it a Norse origin because the name Niellsson is common in Scandinavia, brought there by Gaelic settlers in that country, and likewise in Denmark, where it has become Nigel.
The early Norsemen had no surnames but took such names as "Sword-wielder" or similar warlike names, and the very earliest written works of Iceland and Scandinavia declare that the name "Niellsson" is of Irish origin, which has no meaning in the languages of the Scandinavian nations. The Scandinavians adopted Irish and Scottish clan names, and brought such names as "Jansen," "Johanssen," and "Neallssen" into Scandinavian usage as well as that of Gaelic origin who settled there.
Those of the names Nelson and Neilson may rest assured that the name is of Irish origin, and belonged principally to Ulster, and was in high esteem in ancient times when Niall of the Nine Hostages raided the Britons and waged war against the Romans; written in Gaelic Mac Neill.