The surname MacLeod means ‘son of Leod’. The name Leod is an Anglicization of the Scottish Gaelic name Leòd, which is thought to have been derived from the Old Norse name Ljótr, meaning ugly. Clann means family, while mhic is the genitive of mac, the Gaelic for son, and Leòid is the genitive of Leòd. The whole phrase therefore means The family of the son of Leod.
The Clan MacLeod of Lewis claims its descent from Leod, who according to MacLeod tradition was a younger son of Olaf the Black, King of Mann (r.1229–1237). However, articles have been published in the Clan MacLeod magazine which suggest an alternative genealogy for Leod, one in which he was not son of Olaf, but a 3rd cousin (some removed) from Magnus the last King of Mann. In these alternative genealogies, using the genealogy of Christina MacLeod, great granddaughter of Leod, who married Hector Reaganach (McLean/McLaine) these articles suggest that the relationship to the Kings of Mann was through a female line, that of Helga of the beautiful hair. The dating of Christina’s genealogy and the ability to line it up with known historical facts lend a great deal of authenticity to the claims of the authors.
MacLeod tradition is that Leod who had possession of Harris and part of Skye, married a daughter of the Norse seneschal of Skye, MacArailt or Harold’s son who held Dunvegan and much of Skye. Tradition stated that Leod’s two sons, Tormod and Torquil, founded the two main branches of the Clan MacLeod, Siol Tormod and Siol Torquil.[4] Torquil was actually a grandson of Tormod; Torquil’s descendants held the lands of the Isle of Lewis until the early seventeenth century when the Mackenzies successfully overthrew the Lewismen, partly with the aid of the Morrisons, and the MacLeods of Harris (Siol Tormod). Younger branches of Siol Torquil held the mainland lands of Assynt and Cadboll longer, and the Isle of Raasay until 1846. Siol Tormod held Harris and Glenelg on the mainland, and also the lands of Dunvegan on the Isle of Skye.
Leod, according to tradition, died around 1280 and was buried on the holy island of Iona, where six successive chiefs of the clan found a last resting-place after him.[5]
A DNA project studying the Y-DNA of males bearing surnames associated with Clan MacLeod found that the vast majority of the men tested had a Haplogroup of R1b, which is the most common Haplogroup in the British Isles. A total of 32% of all men tested, who were also in this R1b Haplogroup, also shared the same Haplotype and showed this group shared a common ancestor.
According to the study, this 32% of MacLeods tested had a common ancestor within 1000 years (some will have a common ancestor earlier but all who match with another of the surname with 23/25, 33/37, 62/67 markers share the same more distant ancestor), thus this Haplotype is considered to show the founding lineage of the Clan MacLeod. While the study could not prove a “Viking” origin of the clan, the study claimed the DNA of this group showed that the clan was founded by a man who could have originated in Scotland or the Isle of Man. It should be noted however, that the R1b haplogroup is found at 30% frequency in Norway and that the studies of the haplogroup R1b are very fluid