Mac Amhlaoibh and Mac Amhalghaidh (Irish septs)

Mac Amhlaoibh and Mac Amhalghaidh are two different Gaelic patronymic names with different origins and meanings, but which share the same or similar Anglicisations. These Gaelic names are borne by at least three unrelated native Irish clans or septs (a division or part of a clan).

The Mac Amhalghaidh sept was historically centred at Ballyloughloe in Co Westmeath; the Mac Amhlaoibh sept of the MacCarthy family was centred at Newmarket; and the Mac Amhlaoibh sept of the Maguire family was centred in the barony of Clanawley in County Fermanagh.

Today Anglicised forms of Mac Amhlaoibh and Mac Amhalghaidh include: Cauley, Caully, Cauly, Cawley, Cawly, Colley, Gawley, Macaulay, MacAuley, Macauley, MacAuliffe, MacAwley, MacCauley, MacCawley, MacGauley, Magawley, Magawly, McAulay, McAuley, McAuliffe, McAuly, McCaulay, McCauley, McCaully, McCauly, McCawley, McCawly, McGauley, MacAulay, McCowley, McColley, Macauley, McCooley, and Oliffe.

The Mac Amhalghaidh sept occupied lands located in what is today western Co Westmeath and northern Co Offaly. The heartland of the family was near Ballyloughloe, within the barony of Clonlonan, Co Westmeath, and was known in Elizabethan times as "MacGawleys Country". The sept derives its name from the Old Irish personal name Amhalgaidh. According to MacLysaght, the eponymous ancestor of the sept was an Amhalgaidh who lived in the 13th century. The sept is considered to be of native Irish descent. One pedigree of a family within the sept reaches back to Niall of the Nine Hostages and is stored in the genealogical office in Dublin. A genealogy of the sept is recorded in The O'Clery Book of Genealogies which is thought to have been written by Cú Choigcríche Ó Cléirigh in the 17th century. The genealogy is titled "Genelach Meg Amhlaibh Locha Luatha" and runs as follows:

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