Stephen Baxter 
Time’s Tapestry 

Includes all four novels: Emperor, Conqueror, Navigator, Weaver Collected for the first time in one complete volume.An epic series of counter-factual historical thrillers with a plot that weaves a story over a thousand years in the making. From the decline of the Roman Empire and the emergence of Britain to the discovery of America and the modern world of World War Two, follow the threads of this superb alternate history.