Throughout history, great and terrible events have often hinged upon luck. Tiny changes can produce profoundly different results. We all ask 'what might have been?' about our own lives, now award-winning historian Andrew Roberts has asked a team of 12 leading historians and biographers what might have happened if major world events had gone differently? Each concentrating in the area in which they are a leading authority, historians as distinguished as Antonia Fraser (Gunpowder Plot), Norman Stone (Sarajevo 1914) and Anne Somerset (the Spanish Armada) consider: 'What if ...?' Robert Cowley demonstrates how nearly Britain won the American war of independence. In her first publication since her acclaimed GEORGIANA, Amanda Foreman muses on Lincoln's Northern States of America and Lord Palmerston's Great Britain going to war, as they so nearly did in 1861. Whether it's Stalin fleeing Moscow in 1941(Simon Sebag Montefiore), or Napoleon not being forced to retreat from it in 1812 (Adam Zamoyski), the events covered here are important, world-changing ones. George W. Bush's former White House advisor David Frum considers a President Al Gore's response to 9/11, while Simon Heffer posits a Heseltine premiership had Margaret Thatcher been assassinated by the I.R.A. in Brighton. Conrad Black wonders how the United States might have entered the Second World War if the Japanese had not bombed Pearl Harbor. All 12 essays are thought-provoking and scholarly. Here is a fascinating and often horrifying parallel universe - a universe that so easily might have been.