Hereditary patronymic surnames, O (“grandson of”) and Mac (“son of”), were a central part of Gaelic Irish culture from at least the 11th century, testament to the deep need for public markers of family membership.

This was not the product of some mystical Celtic yearning for blood connection. Far from it.

For almost 1,000 years, the main unit of Gaelic society was not the nuclear family as we conceive it, but a very particular version of the extended family, the derbhfhine, all the descendants of a common great-grandfather.

Among other things, property ownership rested with the derbhfhine, not the individual. So what you could own depended on who your kin were.

No wonder genealogy loomed so large and surnames that signalled kinship were so important.

The name you bore was transparent to those around you, not just, as today, a convenient marker, but instead laden with resonance: stories, possessions, reputations, feuds, homeplaces . . . Gaelic surnames were deeply ingrained in everyday social interactions, as vital and ordinary as language or weather or food.

Imagine, then, the reactions of the Gaels when the first English arrived. John Bird? George Winterbottom? William Featherstone? The initial response must have been simple hilarity.

How could there be people with such ludicrously opaque names, telling nothing of parentage and kin?

The laughing can’t have lasted long. Over the course of the long, catastrophic 17th century, the old Gaelic institutions crumbled under the weight of the English conquest and took with them the centrality of Gaelic surnames.

And after only a few generations, those whose grandparents had laughed at the opaque stupidity of English names were having their own names mangled into opacity by English-speaking administrators: Harrington, Waters, Rabbit, Kidney, Boner . . . all names deriving from perfectly traditional and transparent O and Mac patronymics and all stripped of meaning to force them into English.