Who would be the last Welsh referee who achieved notable international success/ Or indeed Irish for that matter? I'd never really considered that until the above post.
Damien McGraith (Republic of Ireland) went to Euro 2016 as one of Willie Collum's ARs
Eddie Foley of Cork was at Euro 2000
Alan Snoddy was the last Northern Irish referee at a major tournament:
At the 1986 World Cup Snoddy was appointed to referee the game between Morocco and Portugal in Guadalajara which ended 3–1 to Morocco. In the 1990 World Cup Snoddy refereed the game between Colombia and West Germany which ended 1–1 at the San Siro in Milan.
The one glaring omission to major tournaments was Alan Kelly - one of the best referees to come out of the Republic of Ireland - his move to the USA put paid to being selected for tournaments after 2013. The only FIFA tournament he went to was as Video Assistant Referee for the 2019 FIFA U-20 World Cup in Poland - so no on-field games.