How can a history book contain nothing about history (hint: it is called political history...)? This is merely a book that tries to characterise MT's politics, opinions, collaborators (etc) while it assumes that you know everything about the facts.
The book is structured in chapters that cover major policy areas, like Europe, the Fawklands, The Unions, etc. It doesn't follow a strict chronological order. It contains absolutely no information about the facts, what happened and when, and why each was important.
The most striking example is in the Europe chapter and concerns the Bruges speech. Without an explicit overview of the speech, MT's arguments and its impact to other european leaders or countries, the author assumes that you know all about it and covers 25 pages with endless arguments about whether MT changed her opinion on Europe in the 80s or was anti-european altogether. Who cares? How am I supposed to follow these arguments while I have no clue about the actual speech? I was barely born back then.
Another example is the Union chapter. I expected to read about how divided the UK was at the time. I expected to read about incidents that shaped the politics. Yet there was nothing remotely close the the lucidity of Andy Beckett's "When the lights went off" (which I happened to have read just before this book).
In short, only buy the book if you were an adult in the 80s and followed UK politics closely. Or if you have already read another couple of books on MT. If you are looking for an gentle history of "the politics and the social upheaval of the 80s", stay away.