McConnells in Londonderry - maybe

There were actually two major migrations of people from Scotland to Ireland who ended up with the surname McDonnell/MacDonald/McConnell. The earlier migration was before the Reformation, so they were Catholic (and most of those remained Catholic, as did the McDonnell's in my family). The later migration was after the Reformation, and, as already explained, was overwhelmingly Presbyterian. Antrim was the initial destination for both groups, but they spread later to other counties. Dunluce Castle dates to the earlier period. It was built in the 13th Century by Richard Óg de Burgh, 2nd Earl of Ulster, who was not a McDonnell, but later came into McDonnell hands.

Apart from the Antrim McDonnell's and their relatives in Mayo (described below), there were at least two other septs (or sub-tribes) in Ireland with the McDonnell surname, apparently unrelated to the Antrim McDonnell's (and to one another), living in what are now: (i) County Fermanagh (western Ulster) and (ii) County Carlow (the county names and boundaries came later); so smaller numbers of McDonnell's can also be found elsewhere in Ireland.

The island you mentioned sounds like Rathlin Island, off the Antrim coast, but it was settled by Catholics in the earlier migration and remained/remains largely Catholic, so if you're sure of your Protestant ancestry, that would seem to be ruled out (though there were native Irish who converted over the years, just as some Protestant settlers in Ireland intermarried and became Catholic).

The surname in Irish is Mac Domhnaill, which means “son/descendant of Donal”, but it is spelled MacDhòmhnaill in Scottish Gaelic (with the same meaning). The surname was sometimes anglicized as McConnell, particularly in Antrim, Down, and Tyrone, due to the way it is pronounced by native Irish (and Scottish Gaelic) speakers, with the “dh” being a guttural “g” sound (the O’Connell surname is unrelated, and originated in County Kerry). Although they were Protestant, many of those in the later migration of McDonnell's would still have been able to speak Gaelic, because they were from the Highlands and Islands, which were still largely Gaelic-speaking. Their dialect(s) of Gaelic were still close back then to the dialect(s) spoken in Ulster, so they were able to communicate pretty well with the "native" Irish, unlike most of the Scottish Lowlanders and English settlers (although some parts of the Lowlands were also still Gaelic-speaking at the time). As a result, there were a number of Gaelic-speaking Presbyterian churches in Ulster early on, some of which survived into the 19th century (and at least one, I think, into the 20th century).

The “d” at the end of the anglicized form MacDonald is a later addition, due to the inability of English speakers to hear some Gaelic sounds. MacDonald is the more common anglicized form of the name in Scotland (and among the later, Protestant Scots settlers in Ireland), but McDonnell and McDonald were both used in Ireland. MacDonald was less often used by Catholics, but I've turned up records for my Mayo McDonnell's where the two forms were used interchangeably, particularly after people lost the ability to read Irish.

In his “Lore of Ireland”, Ó hÓgáin explains that the McDonnell’s in Antrim were related to the Scottish MacDonald clan (Clann 'IcDhòmhnaill), having come from Scotland to settle in the Glens of Antrim in the 13th century. By the 15th century, they controlled all of North Antrim. A large number of those McDonnell’s were brought from Antrim to what is now Mayo in the late 14th century, to assist the ruling family of that area, the Anglo-Norman Burke family (the family to which Richard Óg de Burgh, mentioned above, belonged). Some now also live across the border in neighboring counties (the county boundaries were a later creation), and they almost all remained Catholic. Those County Antrim McDonnell’s were part of the MacDonald branch known as “Clan McDonald of Dunnyveg”, who were headquartered on the island of Islay and also ruled Kintyre, both places being very close to Ulster, as the crow flies.

There’s a good short article at Wikipedia about Clan McDonald of Dunnyveg, at this link: https://en.wikipedia.org/wiki/Clan_MacDonald_of_Dunnyveg

There's a separate article at Wikipedia which explains the connection of the Antrim McDonnell’s to Clan McDonald of Dunnyveg: https://en.wikipedia.org/wiki/MacDonnell_of_Antrim

In addition, there’s a YouTube video on the family tree of the MacDonald Clan. In the latter part of it, you can see the connections to the McDonald’s on Islay and the McDonnell’s in Antrim. It doesn’t trace all of the many branches, though, so there’s no mention of Mayo. Here’s the url: https://www.youtube.com/watch?v=Z5pW5k61enA

Elwyn and Kevin,

Thank you so much for your lovely replies.

I have had my brother's Y-DNA done many years ago to 67 markers and assigned a Haplogroup of R-A497 and firmly put with a group of Scots/Irish. That is with the Clan Donald DNA project, but I recently noticed that other projects I have joined (Ulster, Scots/Irish, etc) all say that he had only done a "Family Finder" autosomal test and says there uncertain matching in this project and to consider the Big Y. So I will have to look into that.

I do believe they were Presbyterians. At the very least, they were Protestants.

Of course, I realize that when the Pembroke history was done in 1895, Thomas McConnell (who I believe was the one to emigrate, had been dead for 141 years! So to say he was from Londonderry may not mean a thing.

So I think you are suggesting that I visit Antrim and the Island of Islay to commune with my ancestors. Are there museum or heritage centres I should visit?