Very readable, fun, interesting history. It has a lot of good background, a lot of detail on political history of the Social Democrat party. Very insightful. If your interest is in the party as it led up to revolution, this is a great book to start with and the footnotes will help you find others to follow up with. It is 500 pages of the background of the party leaders, Lenin as central of course but with insight into the early party workings; it is not a private personal book about Lenin or a history of the Bolsheviks once in power, but for pre-power Bolshevism, its a great start.