An 80-year campaign for Pendragon, though this book only covers the first half of it in any depth. You'll find an overview of the Anarchy period (495-509), then year-by-year descriptions from 510-531. The chronology after 531 is only covered briefly, with 8 pages for the last 40 years.
In addition there's a bit of info on London and Camelot, plus stats for many of the main characters.
Notes on This Edition
The guts of this book (p. 4-132) are exactly identical to the first edition of
The Boy King. (They were printed off the same paste-up boards.)
Beyond that, there's a new set of title pages, a sort of clumsy set of conversions for 4th Edition
Pendragon (which give magical stats for everything) and an attractive 5-page graphical timeline, drawn from Greg Stafford's original notes for the supplement (and its sequel, which was never produced by Chaosium).