I have just bought The Bog People by P.V Glob, I read it years ago when I worked at Leeds University Library and have wanted a copy for yonks.
I first became familiar with the Bog People when studying Seamus Heaney in my undergraduate degree, who had a bit of an obsession with them, especially in his 1975 collection North. In a nut shell, bodies have been found in bogs in Northern Europe from as far back as the Iron Age, perfectly preserved due to the chemical balance of the bogs, often showing signs of torturous murders, presumed to be sacrificial.
This book by P.V. Glob is fascinating, and was groundbreaking in its publication in 1965, though has lost some of its edge over time, as views about the nature of the deaths (and in some case even the genders) of the bodies are fairly contested. Many now believe that some wounds weren't infact inflicted while they were living, but rather incurred due to the weight of the bogs above them. It's a gripping read regardless.
I bought it second hand on Amazon, unable to find a copy in any of the bloomsbury second hand book shops, and the seller included an article from the Guardian in 1998 inside of it, which was a very nice touch.
It's incredible the extent that these bodies have remained in tact (google them!), it's no wonder that when many of them were found, it was assumed that they were recently murdered people.
There's more information at this website, the site's a bit style over substance for my liking, but there are some oral histories and such on there which are quite interesting.
Also, an interesting read about Heaney's bog poems here.
And a more contemporary news piece about the bog people from the National Geographic.
Strange Fruit Seamus Heaney
Here is the girl's head like an exhumed gourd.
Oval-faced, prune-skinned, prune-stones for teeth.
They unswaddled the wet fern of her hair
And made an exhibition of its coil,
Let the air at her leathery beauty.
Pash of tallow, perishable treasure:
Her broken nose is dark as a turf clod,
Her eyeholes blank as pools in the old workings.
Diodorus Siculus confessed
His gradual ease with the likes of this:
Murdered, forgotten, nameless, terrible
Beheaded girl, outstaring axe
And beatification, outstaring
What had begun to feel like reverence.