The origin of his name is a good subject, so I'll go with that.
The name "McNair" and the fact that he's a border collie would probably give you a clue that he has Scottish heritage. "McNair" is one of several Anglicized forms of a name that is considered to have multiple origins. Two of these are that it could derive from the the Gaelic name "Mac Iain Uidhir", meaning "the son of sallow John", or "Mac an Oighre" meaning "son of the heir".
I think this is also a good segue into some info on some of my 'sona's family history. He comes from a very old family.
Shane is a descendant of Presbyterian Ulster Scots who emigrated to America in the 1700s before the Revolutionary War. They eventually ended up settling in the southern Piedmont region of North Carolina. Some of the men in Shane's family around that time served in the British Army during the French and Indian War, and later supported the Patriot cause during the Revolution. One of the family's favorite oral histories about this time recalls how a couple of the McNair men were among the militiamen who drove the British forces under General Charles Cornwallis out of Charlotte, North Carolina when they were occupying the city (In real life, Cornwallis actually later wrote that Charlotte was "a hornet's nest of rebellion"). It's said that these McNair men served under Francis Marion, the famed "Swamp Fox" (who I'm sure would be a literal fox in Shane's canon universe), during his guerilla campaign against the British Army and Loyalist militias in the south.
Due to a lack of records, Shane doesn't really know anything about his family prior to their migration from Scotland to Ireland in the 1600s (the beginning of the Ulster Plantation period of their history). However, according to Shane's father, some of his very distant ancestors going way back to the Late Middle Ages were "border reivers". These were unruly and fierce mounted raiders who survived by plundering the Anglo-Scottish border region - mostly by livestock rustling - but they would also steal household goods and valuables, or even kidnap people to hold for ransom. In those days, the border region was a troubled land ravaged by frequent wars between the English and Scots. Neither kingdom was able to effectively maintain law and order there, especially in remote areas, and it was difficult or impossible for Shane's ancestors to survive by honest means. The world they lived in was like a medieval version of Mad Max, and the borderers were something like biker gangs who relied on the protection of the clan system and strong kinship ties. Border reivers had no particular loyalties to either Scotland or England, and due to being skilled horsemen they would occasionally fight as light mercenary cavalry formations in the armies of either kingdom. Sometimes they would spontaneously switch sides whenever it suited them. Borderers from the Scottish lowlands often had kin living in the northern English counties, and vice versa. The age of the border reivers ultimately started to die out in the 1600s under the rule of King James VI of Scots (later James I of England) who aggressively tried to snuff them out. It isn't really known how the McNair family came to settle in Ireland during the 17th century, or exactly when or under what circumstances they finally got out of the business of border raiding.
