The guide, Naval Self-discipline, was written by Christopher Biden within the mid nineteenth century and covers the Royal Navy’s guidelines on mutiny.
The president made a considerably confused reference to his ancestor throughout his go to to Northern Eire in April.
In his speech in Belfast’s Ulster College, Mr Biden referenced a George Biden who in “1842, may have been 1828; I can’t keep in mind — it’s a kind of two dates — had written the foundations — the foundations of mutiny for the British Navy”.
Mr Biden, who’s happy with his Irish ancestry, joked: “Effectively, at the least that half is constant…the mutiny.”
Mr Sunak may also current Mr Biden with a personalised Barbour jacket, made close to his Richmond constituency.
The Bedale-style jacket is embroidered with the phrases “Mr President” on the entrance pocket as a substitute of the Barbour branding.