Gilmalagon is a witness
We have discovered that the most probable original Gaelic form of our name is Mac Ghille Mochuda, literally son of the devotee of Mochuda. (See the blog piece on Celtic Origins). In the year 1112 AD one Gilla Mochuda O'Rebhacain became the 39th Abbot and Bishop of Lismore in southern Ireland, in succession to the 6-7th Century Mochuda (St. Carthage). He was abbot and bishop for just one year. Now interestingly as Gilla Mochuda was relinquishing his post, the clan name appears in the Annals of another Abbey, this one across the Irish Sea, in the south of Scotland.
G.F. Black, sometime the Librarian of New York's Central Library, who wrote the authoritative book, The Surnames of Scotland, thinks that the earliest reference to the anglicised name McIlhagga is in the 12th Century and comes from the Gaelic Giolla Mo-chuda through a Latinised form, namely 'Gilmagu'. This is found in the Latin charter relating to Kelso Abbey known as Liber S.Marie de Calchou, the 'Book of St. Mary, Kelso'. Kelso Abbey is in the Scottish Borders, a monastery founded by the sainted King David (1085-1153) and in precedency only second to the Priory of St. Andrews. The charter grants to Gilmagu and to his heirs a specific portion of land which the charter describes in detail, though in such a way that might make it very difficult to identify today! The charter states the conditions on which the land will be held and the rent to be paid, twenty shillings a year. Gilmagu is probably the same person as Gilmalagon who witnessed another gift of land in Kelso, from Duuglas (Douglas) to Theobald the Fleming in 1150. About this time other possible variants of the name Gilmagu appear first in the history of Glasgow Cathedral (Gillemachoi) and in Dumfriesshire where we find Michael McGilmocha and Achmacath McGilmotha among the chief men of the lineage of Clen Afren in 1296.
Where did Gilmagu hail from? What happened to the land which he and his heirs were gifted? I'm afraid these must remain open questions. There may however be a clue to Gilmagu's origins in another place. Interestingly, in another Border Abbey, that of Melrose, we have the probable anglicised clan name as one witness to yet another gift of land, this time a gift to the Abbey. Among these witnesses were Duncan, son of Gilbert, Earl of Carrick and also the Steward of Carrick, one Gillescop MacI(l)hagain. The Steward of Carrick would no doubt have been responsible for Earl Duncan's household and the management of his lands. Significantly Carrick is the part of Ayrshire where we find, 300 years later, our next clan appearance in the villages of Colmonnel and Kirkmichael. Was there a link from Gilmagu of Kelso to MacIlhagain of Carrick? Was Gillescop, the Steward of Carrick the founder of a dynasty in the West of Scotland from which many of us hail today? I'm afraid these questions must also remain unanswered so many years 'down the line' of clan descent.
A last word on the Medieval Period must be a reference back to Ireland. As with the 39th Abbot and Bishop of Lismore, the name Giolla Muchuda was being adopted as a Christian name, another example of which is the earliest known Cassidy poet, Giolla Mochuda Mor O'Caiside. In 1147 O'Caiside composed Benshenchas, literally 'The Lore of Women', which contains a list of famous married women in the ancient world and in Irish history and literature. But not only did the adoption of our clan name as a Christian name become popular. It was also adopted in another way. St. Mochuda's fellow Kerryman, Ailinn O'Sullivan became bishop of Lismore in the mid-thirteenth century. He initiated the practice of the O'Sullivans paying particular devotion to 'our' saint. As a result the practice grew up among one of the leading families of the O'Sullivans of using Giolla Mochuda as a kind of title. A famous recorded use of Mac Giolla Mochuda in this way was by Conor, who is recorded as having slain Donal O'Sullivan Beare in 1563. His family, unlike much of the old Gaelic aristocracy, has a clear line of descent right down to the present day, holding the title in the slightly evolved form of 'The MacGillycuddy of the Reeks'. The present holder of this title is Richard Denis Wyer MacGillycuddy who is we believe resident in France.