If there's one thing we know about Joe Biden, it's that he's proud of his Irish roots.
The new US President never tires of talking up his background on the Emerald Isle – nor namechecking his relatives, the Finnegans from Co Louth and the Blewitts from Co Mayo.
Ireland, the 79-year-old has said, is "written on my soul."
Cynics might compare Biden to the legions of other Americans who claim, with little evidence and less knowledge, that their ancestors hail from Ireland.
But the former vice-president really does know his stuff when it comes to the specifics of the country he sees as his own.
One one side, Biden's great-great grandfather, Owen Finnegan, hailed from the Cooley Peninsula in Louth. After marrying Jean Boyle in 1839, Owen fathered four children – including, in 1840, James Finnegan, Biden's great grandfather.
The family moved to New York in the 1840s, and James lived there for years until both his parents died in 1874.
Then James and his wife, Catherine Roche, made the move to Scranton, Pennsylvania – which is where Biden himself was born more than 150 years later.
The couple had six children – one of whom was Ambrose J Finnegan, Joe Biden's grandfather.
On the other side, Biden's great-great grandfather Patrick Blewitt was born in Ballina, Co Mayo, in 1832. He moved to the US in 1850, where he settled in (you guessed it), Scranton, Pennsylvania.
He worked as a mining inspector, before graduating as a civil engineer. In 1907, he was elected to the US Senate.
One of Patrick's four children, Geraldine, married Ambrose J Finnegan – Biden's grandfather. Together they had Jean, Biden's mother, who was born in 1917.
Biden really does emphasise his Irish roots at every opportunity: even today, in an emotional send-off speech in Delaware, the incoming US boss couldn't resist reaching deep into his Irish heritage for a quote. His choice of reference? James Joyce.
