What is Joe Biden’s Irish heritage?

Joe Biden has arrived in Belfast, Northern Ireland, to mark the 25-year anniversary of the Good Friday Agreement.

For an American president with deep Irish roots, it won’t be a typical trip to the ancestral homeland.

Mr Biden is expected to meet representatives from five Northern Irish political parties at a time when the Democratic Unionist Party (DUP) is continuing to boycott the devolved power-sharing government in Stormont in protest at post-Brexit trading rules that treat the province differently to the rest of the UK.

US national security spokesman John Kirby said Mr Biden would not attempt to pressure the DUP into returning to the assembly, commenting: “The president will have the opportunity to engage with the political parties of Northern Ireland before his speech [at Ulster University], and as we’ve said, he looks forward to continuing to engage them as we work to improve the lives and livelihoods of all communities there.”

Mr Biden has, however, been fiercely critical of former British prime minister Boris Johnson in the past over his threat to scrap the Northern Ireland Protocol of Britain’s EU withdrawal agreement, a move that risked jeopardising the hard-won peace secured by the Good Friday Agreement in 1998, which drew a line under three decades of deadly sectarian violence during the Troubles.

The president, who was born and raised among Irish-Americans in Scranton, Pennsylvania, rarely misses an opportunity to express his pride in his heritage or quote one of the many Irish poets he admires such as WB Yeats and Seamus Heaney.

”Every time I’d walk out of his house in Scranton, when I lived there for a while, he’d look at me and say, ‘Joey, remember, the best drop of blood in you is Irish,’” he said of his grandfather on St Patrick’s Day last month.

Mr Biden last visited the island of Ireland in 2016 while serving as Barack Obama’s vice president but traces his roots, on his mother’s side of the family, all the way back to Edward Blewitt, his great-great-great-grandfather, of County Mayo and to the Finnegan family of County Louth “who boarded coffin ships to cross the Atlantic more than 165 years ago”, in his telling.

According to research by the Irish Family History Centre, Edward Blewitt was a geographical surveyor from Ballina, probably born in 1795, whose son Patrick left Ireland during the Great Famine in 1850, returning a year later to bring his parents and three siblings to the US aboard the SS Excelsior to begin a new life.

After a period in New Orleans, it was Patrick Blewitt who first settled the family in Scranton in 1860, where he worked as a mining inspector, also travelling to South America for his profession.

His son Edward F Blewitt – born in 1859 and named in honour of his grandfather, who would drown in a mining disaster in 1872 – qualified as a civil engineer before running for office and being elected to the Pennsylvania State Senate in 1907.

He and his wife, Mary Ellen Stanton, had four children, one of whom was Geraldine Blewitt, whose later marriage would bring together the two sides of Mr Biden’s mother’s family.

The other branch of the family tree, the Finnegans, can be traced back to John Finnegan and Mary Kearney who harvested seaweed in the Cooley Peninsula off coastal County Louth. Their son Owen left Ireland for the US in 1849 with his wife Jean Boyle and four children, as well as a brother and three cousins.

Owen Finnegan and his family settled in Ovid Township in Seneca Falls, New York, where he opened his own business as a shoemaker.

He passed away in poor health in 1874 while his son, James Finnegan, relocated to Olyphant, Pennsylvania, close to Scranton, with his wife Catherine Roche and six children, including a son, Ambrose Finnegan, whose marriage to Geraldine Blewitt would result in the birth of Mr Biden’s mother, Catherine Eugenia Finnegan, in 1917.

She in turn would later marry Joseph Robinette Biden Sr – whose own family history can be traced back to stonemason William Biden, who left Westbourne, West Sussex, for Maryland in 1820 – with whom she had a son, Joseph Robinette Biden Jr, on 20 November 1942, the eldest of four siblings.

Of his father’s inconvenient English background, Mr Biden said last year: “He had the saving grace, on his mother’s side, of having a Hanafee from Galway. That’s the only thing that saved him. And you all think I’m kidding. I'm not.”

Following his trip to Northern Ireland this week, Mr Biden will visit the Republic of Ireland where he is set to meet distant cousins in County Louth on Wednesday and deliver a public address at St Muredach’s Cathedral in County Mayo on Friday evening before jetting home to Washington aboard Air Force One.

Speaking ahead of his visit on Sunday, Irish prime minister Leo Varadkar said: “Since [John F] Kennedy there hasn’t been as Irish American a president as Joe Biden and we’re really looking forward to welcoming him home.”