This is the centrepiece of the emortality series, and was the one that I remember most strongly from my previous read of the books.
It's an autobiography of Mortimer Gray, one of the first generation of true emortals. Although his life takes many twists and turns over the five or six centuries that the book covers, the thread that runs through is his work writing a history of death.
This allows Stableford to blend the story of Gray's life with his commentary on how people of the past (including us, obviously) dealt with the omnipresence of death. This is interesting stuff, too, and a hell of a lot more deep and thoughtful than most science fiction.
In the background is the huge scope of future history that Stableford has built these books on. This world-building is, to my mind, a lot more plausible than most. There are a few places in which massive, implausible (or unlikely) events occur, but I find that the way he describes society reacting to them feels right. For instance (this will come up more in my review of the next book) the almost totally ineffectual reaction to the climate and (in his world) population crises of the twenty first century.
A great piece of work. Read it.