This appears to be a book-of-the-TV-series dating from 1981, revised in 1987 (my copy is a 1994 reprint). I imagine the TV series must have been reasonably interesting; sadly, for much of the book I found myself wishing for more relevant illustrations and better maps.
Wood takes a straightforward tack of structuring his narrative around nine individuals from Boadicea to William the Conqueror (not that I would really have counted either of them as belonging to the 'Dark Ages', but there you go). It doen't always work. One of the nine is the Sutton Hoo Man, and it's difficult to construct a good narrative around someone when the only thing you know for sure about him is that he is dead. And the chapter on Athelstan promised to open our eyes about him and also reveal why he has been allowed to fall into obscurity; I am afraid I found my eyes glazing rather than opening, and if there was an explicit explanation of why we never hear much about him I missed it.
However, the chapters on King Arthur, Offa and Alfred were all good. (The other two are on Eric Bloodaxe and Ethelred the Unready.) I especially enjoyed the Alfred one; I found myself musing on the history of the Danelaw, which as a result of Alfred's efforts seems to have been completely incorporated into the English polity, disappearing completely as a political entity in its own right. The Danelaw extended much further both south and west than I had realised, including both the ancestral origins of my mother-in-law in Lincolnshire and of my father-in-law in Derbyshire. And I realised something very important that had never occurred to me before (but perhaps should have):
I married a Viking.
Top UnSuggestion for this book: It, by Stephen King.