The Northern Irish 6 counties did not want to unify with Ireland when Ireland was born in 1919. Those 6 were the protestant majority counties, who wished to stay with the UK.
Changing demographics and birth rates over the following century, increasing secularisation in the Republic, and increasing numbers who simply don't care about religion makes that far less of the issue.
Just as those ruling in London no longer see themselves as Norman French, or in my UK county Danish.
But in ireland it is not only about the english living in north ireland, but more about the irish living there. It was more about catholic vs. protestant.
Not so easy to dissolve, but I hope the last blood happened long ago enougj for both sides to forget and move on, even if england messes up the deal amd the border becomes an issue again.
This is debatable. It was very close and the large numbers of English retirees in parts of Wales that made it seem that Wales voted to leave. Brexit is very much an English project.
Citation: https://www.theguardian.com/uk-news/2019/sep/22/english-peop...