Find out about 12 of the biggest and most brutal battles in the history of the world, from Thermopylae in 480 BCE right the way through to Operation Desert Storm in 1991, taking in Cannae, Agincourt, Lepanto, the Siege of Yorktown, Trafalgar, Waterloo, Gettysburg, the Somme, the Battle of Britain and the Siege of Stalingrad.