One quarter of all the 500+ Garveys listed in the Griffith Valuation were in Co Mayo, but the origin of this group is not well understood. Rosemary Garvey's book, "Kilkenny to Murrisk", is probably the most complete history of the Mayo Garveys that is available. According to her account, there were no Garveys holding land in Mayo before about 1575. So Mayo is not an ancient homeland of the Garveys, but rather was a place to which some Garveys migrated during the reign of Queen Elizabeth I. At that time several Garveys acquired land in the area under a redistribution of Church land that was then occurring. The most famous of these was the family of Archbishop John Garvey who had land at Murrisk (civil parish of Oughaval). Relatives of the Archbishop settled at Falduff and Tully (civil parish of Kilgeever). Other Garveys acquired land and built castles at Lehinch, and Lissatava (civil parish of Kilcommon). These places match up approximately with some of the greatest concentrations of Garveys in Mayo in the Griffith Valuation some 275 years later. No settlement by Garveys at Shrule or Drum is mentioned.
The only account given in the book of the origins of the Garveys in Mayo is that most of the ones who settled in the Oughaval-Kilgeever (Murrisk) area had migrated there from the city of Kilkenny. The book claims that they had arrived in Kilkenny less than 100 years before they moved to Mayo. Nothing is known of them before that time - nor is any speculation made as to the origins of the other Garveys in Mayo.
On the other hand.....
The historical account claims that a group of Garveys (O'Gairbhain branch from County Meath) moved into the area of Mayo near Crossmolina in the early 1200's. In that case there would have been Garveys in Mayo about 350 years earlier than the beginnings of the Garveys in Mayo described in Rosemary's book.
This historical account is probably based upon a document written by the Genealogical Office of Ireland in the 1840's manuscript called GOMS 175. As stated in Rosemary Garvey's book, the manuscript was "only as good as the information available at the time". She thinks they got it wrong. Her evidence to the contrary is a document written in 1575 called The Composition of Connacht which listed all the major landholders. The lack of any Garvey landholders in Mayo is taken to indicate that there were no Garveys.
This historical account claims that the Garveys who settled near Crossmolina in the 1200s were a branch of the Garveys called O'Gairbhin. It goes on to state that this Gaelic name would be more accurately translated as Garvin - but was later corrupted to Garvey.
It would be interesting to learn what is known of the origin of the names of the civil parish and townland called Kilgarvan (shown on some maps as Kilgarvey). They are located in the northeast section of Mayo just east of Ardagh and Crossmolina. A place name beginning with "Kil" usually indicated a church or religious settlement.
A detailed account of the life of Archbishop John Garvey can be found in an article by Brian McCabe titled "An Elizabethan Prelate: John Garvey (1527-1595)" (Riocht na Midhe, Vol 9, No 3, pp. 89-101 (1993)). It can be ordered at your local library through inter-library loan.
Rosemary Garvey's book quotes an Oct 30, 1913 letter to F.C. Garvey from the Office of Arms, Dublin Castle (signed by G.D. Burtchnell, Athlone Pursuivant Registrar). This letter states that a mistake had been made by their office in 1843 [presumably in the drafting of GOMS 175] when the County Down Garvey's Coat of Arms was mistakenly assigned to the Archbishop's descendants. Mr. Burtchnell states that he had recently located the Coat of Arms granted to the Archbishop (shown at left). The lower left quarter of that shield is the Coat of Arms of the Butlers (the family of the Archbishop's mother). The arms in the upper right quarter belong to the Dowdall family (the Archbishop's paternal grandmother's family). Those same arms could have equally been claimed by the Archbishop's brothers. However the Arms granted to the Archbishop in 1567 were personalized by two design choices (that were likely made by the Archbishop himself): the ship ("a galley sable") in the upper lefthand corner, and the motto of "Velo an Remis". Rosemary Garvey had little faith in the GOMS 175 genealogy any farther back than the Archbishop's parents John Garvey and Finola Butler (of the House of Ormond, from Burrishole, Co Mayo). However the presence of the Dowdall quarter seems to confirm the genealogy one generation further back to the Archbishop grandparents Denis O'Garvey and Gormolina Dowdall (daughter of Patrick Dowdall of Ardmas, Co Mayo).
Rosemary Garvey mentions that one story has it that Archbishop Garvey's father may have been a captain in the army under the Earl of Ormond. This reference cites that particular Earl as Sir Pierce Butler (1467-1539), the 8th Earl of Ormond. So that may be how the Archbishop's father met his mother, Finola Butler. However GOM 175 has a handwritten notation that says that Finola was of the Burrishoole, Co Mayo Butlers (as opposed to the more famous Ormond/Kilkenny Butlers). Edmund Curtis (p.49) refers to these Co Mayo Butlers as the "Butlers of Achill" and says that they acquired the Mayo lands in the 1200's. He also states that Finola was the last of that line of Butlers of Achill, and that after her marraige to John O'Garvey that those lands past into the possession of Thomas Butler (1532-1614), 10th Earl of Ormond.