Who Do You Think You Are? (BBC2)

The Black Mummy Mystery (five)

The makers of family history series Who Do You Think You Are? did what many thought impossible - made Jeremy Paxman cry.

It was more of a sob than a flood of tears, but enough to take you aback when the blubberer is an interviewer known for his Rottweiler technique in interrogating politicians.

Breaking point on his climb up his family tree came on learning the circumstances of the death of his great-grandparents, through TB and exhaustion. "It's a hard life, a very hard life," sighed Paxman, rubbing his eyes.

"You shouldn't go into this family history business, it's just upsetting, there's nothing you can do about it," he said. "Hundreds of thousands of people must have lived and died like that".

Perhaps the thing that got to him was how different it was to his own privileged upbringing in a prosperous Yorkshire family. His great-grandmother Mary, on the other hand, was widowed and left with no income and many children to raise.

Her poor relief was withdrawn after an anonymous letter informed the authorities that she'd had an illegitimate child. She faced the cruel choice of keeping the family together and risking starvation or going into the workhouse and having the family separated. She chose the former, being reduced to living in one room with the seven or eight of her 11 children still at home.

Stories like that made the first series such a hit with viewers, ensuring another batch of Celebrity Family Tree was inevitable. Paxman made out he was a reluctant participant, believing you should live life looking forwards not backwards.

But as "most TV is rubbish", he thought a "bit of social history" might be worth doing.

He was undeniably tetchy with the off-screen interviewer, not wanting anyone to think that researching his family history was a burning issue. He declared himself "interested but not excited".

Pressed by the off-screen interviewer, he demanded: "Ask me a sensible question", adding, "What do you expect me to do - wet my pants?". Now that would have been unusual TV.

Despite the title, The Black Mummy Mystery wasn't five's attempt at a family history programme but about the implications of the discovery, 40 years ago, of the mummified body of a young boy. He was found in a rock shelter in the Libyan desert, a location that set people wondering if someone other than the Egyptians invented mummification.

This isn't a question that occupies most of us but professors of this and doctors of that queued up to offer advice to Italian Dr Savino di Lernia, whose interest in the mummy borders on the obsessive.

A computer model of the Sahara desert going back 10,000 years was built, ancient broken pottery was glued back together, and tales of dramatic climate changes were all part of the story.

But, unlike Paxman's relatives, the mummy's family were hard to trace. Their history has been covered by the sands of Sahara.