Swedish schools teach that the Viking Age ended on a certain date. No one outside of Scandinavia has an idea of what it is, though Swedes become annoyed when other Europeans assume that they are all the descendants of berserkers, in that same way that Australians deny their forebears' unhealthy attraction to other people's sheep. Sometime after the Vikings had passed Sweden was growing into a major European power, and then in the fourteenth century that just faded away. No one mourns the loss of the Swedish empire in the way that they mourn the Dark Ages following the collapse of Rome, but no one wonders why.

Robert Cowley's collection, WHAT IF? offers essays covering the earliest times to the latest - a long, disproportionate essay on the American Civil War is the only evidence of this volume's origins. The contributors include British historians, and other authors, including Caleb Carr, the author of the THE ALIENIST. Carr's short contribution makes interesting reading: asking what would have happened if Napoleon had won the Battle of Waterloo, he looks at Bonaparte's politics controlling his demands at the Congress of Vienna.

But just consider that Swedish example: it is mentioned as a throw away reference to one of Arnold Toynbee's examples in A STUDY OF HISTORY. While Niall Ferguson's 1997 VIRTUAL HISTORY (reviewed: VECTOR 195) had a similar throw away reference to Gibbon describing the Battle of Tours, it was massively contemptuous of the earlier man, as Ferguson was to too many other authors. Now Barry S. Strauss has returned and shows how correct was Gibbon's appreciation. However, the contributors to this volume clearly appreciate other historians, and SF authors of alternate history - Geoffrey Parker's discussion of the Spanish Armada starts with an analysis of Keith Roberts' PAVANE.

No volume like this can be complete, but WHAT IF can be recommended. If the other author's knew Ross Hassig's account of Hernan Cortez's close brush with death they could not have sat comfortably in their American homes as they wrote.