After the referendum I spent a bit of time tracing family history in the hope of an Irish connection.
I actually found my maternal great grandfather (surname Lyster) was listed as Irish in the 1840 census. But there are no birth records I can find, and I believe that grandparents are the furthest back that is acceptable.
Besides that it seems that everybody in my traceable family history on both sides, apart from my maternal grandfather (who was from Monmouth), was from Swansea.
I must be the person with the most Swansea DNA on the planet.