Jeremy Paxman was quite dismissive when it came being involved in this series, and about family history in general. 'I've always thought you have to live life looking forwards, not backwards ... I've had no interest at all in who my ancestors are.'
Little did he know what lay in store.
He first headed north, to Glasgow, in search of the McKays. His maternal great-great grandfather was John McKay, who met and married Mary Nicholas while stationed in Devon with the Royal Artillery.
The pair married in Glasgow, and after his discharge in 1891 he worked as a school caretaker. From the school's log, Jeremy discovered that John died in 1894, leaving behind Mary and nine children. She did not receive his army pension and had no other means to support her family.
Her last resort was poor relief. But her application to the parish authorities was rejected after an anonymous letter snitched on her for having an illegitimate child, an act of such malice that Jeremy was at a loss for words, his anger visible.
His next stop was the tenement, now abandoned, where Mary was forced to raise her brood in abject and unsanitary conditions. The experience was humbling and emotional for Jeremy. 'We're just don't know we're born, do we?' he tells the camera.
He was struck with admiration when he discovered that Mabel, his grandmother, left the Glasgow slums and joined the Salvation Army, who at that time assisted in the emigration of the poor.
It emerged that Mary emigrated to Canada with six of her children, while Mabel stayed, settled in Yorkshire and gave birth to Joan, Jeremy's mother.
Jeremy uncovered a picture of Mary, taken in Canada towards the end of her life. It showed an indomitable woman who refused to let life drag her down. She had, as Jeremy said, come through the other side.
The revelations did not end there. Researching his father's side proved equally emotional. His great-grandfather, Thomas Paxman, died of TB, aged 35, in 1888. Less than two years later his wife, Mary Jane, followed him to his grave, dying of TB and exhaustion.
Arthur Paxman - Jeremy's grandfather - was orphaned at the age of 10, with his brother Thomas. This tragic saga affected Jeremy once more. 'You see, you shouldn't go into this family history business, it's just upsetting,' he told the camera once the emotion had subsided.
'God we have it easy,' he said, echoing the sentiment expressed upon seeing Mary McKay's tenement slum.
In a world where it was literally a case of survival of the fittest, families closed ranks and looked after their own, no matter how distant the blood ties. Nevertheless, Arthur must have been astonishingly tenacious to lift himself out of this desperate start to his life.
At 12 he was working as a worsted spinner, but grew up to be a travelling sales representative in textiles, becoming sufficiently prosperous to send his son, Jeremy's father, Keith, to a public school.
Less emotional, but no less revelatory, was the discovery that the Paxmans originated in Framlingham, Suffolk. Jeremy found out that the Paxmans of East Anglia were descended from a Roger Paxman, whose name first appears way back in 1387.
Roger initiated the name, 'upgrading' it from 'Packs-man' - 'man with a pack' - to 'Pax-man' - 'man of peace'. Either way, Jeremy's long-held belief that he came from a long line of Yorkshire folk had been demolished. Instead, his roots lay in rural Suffolk.
Roger, to Jeremy's consternation, went on to become mayor and a member of parliament, or a 'charlatan politician' as Jeremy describes him.
'I didn't think I could go any lower, but we're doing well so far,' he said.
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