I'd certainly believe that Irish people are related to eastern Europeans - definite physical resemblance, not to mention a similar sense of humour and work ethic and family values. Not so much the Hungarians, but the Poles and Romanians, yes. Also the Baltic people - Lithuanians, Estonians, Latvians.

There was also a lot of traffic up and down the Atlantic coast - Spain and France especially.

And obviously Britain, lots of back-and-forth between the two islands.