This is a book on 'radical' history by someone who does not like radicalism, and as such it cannot help but be deeply dishonest. In many cases Vallance explicitly has a go at other radical histories (dubbed disparagingly as 'marxist') for their overly radical tone. While I am not a marxist and find those dogmas within historical writing to be very tiresome, I also do not agree with Edward Vallance's take on 'radicalism', which is in fact nothing more than the 'rights' and liberal values that have already been attained within British politics. These weak voting rights and equally weak protective shields within parliamentary democracy are for him the 'radical' outcome he is pleased with, while any more radical ideas that didn't make it into the mainstream of British politics (or have since been crushed) are kind of brushed aside.
It becomes apparent then that the author has an axe to grind throughout the book: he wishes to debunk more radical accounts of history in favour of a circular logic that says that those movements that resulted in the rights we have now were the true radicalism, while those radical ideas which didn't make it were not to be taken seriously in the first place. There is one deviation from this pattern which is also the most serious dishonesty in the book. The rights of workers, as fought for through many decades and even centuries by the workers themselves, are barely mentioned. The word 'strike' does not appear in the index, nor can I find a mention of the 1926 General Strike that threatened the authority of government (admittedly I started skim-reading towards the end, not wanting to waste too much time on such egregious nonsense so do correct me if it's in there).
In fact the entire history of socialism is bizarrely condensened into a long section about women's suffrage and socialism, with almost all the attention paid to women's suffrage. This is followed by an 'interesting' interpretation of anti-fascist action in Britain (according to him it was affection for parliamentary democracy, not direct action, that defeated fascism - an unprovable assertion but let's not worry about that hey?). I don't even describe myself as a socialist and think that most socialists made grave mistakes in an espousing of authoritarianism which I find highly objectionable, but to write them out of history? This is the dishonesty of propaganda and I would urge you to at least read other sources before blithely taking it seriously as history.
There are some bits that aren't so bad - he joins in a string of recent attempts to rehabilitate Luddites as radicals rather than mere conservative reactionaries. This chapter is probably the best of the book. However it doesn't excuse the general tone of sidelining the radicals he doesn't like (the ones who are *too* radical, in other words).
To give you an example of how strong this author's bias is, he attempts to downplay the radicalism of the Putney Debates (between Levellers and New Model Army leaders during the Civil War) by saying that there was very little talk of universal male suffrage at the Putney Debates. Instead, he says, there was much more focus on the idea that 'every man that is to live under a government ought first by his own consent to put himself under that government'. So keen is he to use this to downplay the radicalism of the Putney Debates that he appears not to notice that this latter idea is far, far more radical than the mere process of voting every few years. If taken to its logical conclusion it undermines the idea of the nation state (whether or not the speakers at the debates intended it that way) and speaks of a radical freedom much greater than that of the freedom to vote. But Vallance is now so caught up in his own intellectual dishonesties that he cannot see that he has incriminated himself from his own mouth. His 'proof' of a less radical interpretation of the Putney Debates actually operates as a proof of his bias.
In conclusion, this is a book of 'radical' history the purpose of which is to defend the status quo. I urge you to read other books instead (or as well, at least) such as Christopher Hill's wonderful The World Turned Upside Down - a book relatively 'unpolluted' by the marxism Vallance hates so much, and much more inclusive and much more fun than this book.