Gallic Wars
The Gallic Wars were a series of military campaigns waged by the Roman proconsul Julius Caesar against several Gallic tribes. Rome's war against the Gallic tribes lasted from 58 BC to 50 BC and culminated in the decisive Battle of Alesia in 52 BC, in which a complete Roman victory resulted in the expansion of the Roman Republic over the whole of Gaul (mainly present-day France and Belgium). While militarily just as strong as the Romans, the internal division between the Gallic tribes helped ease victory for Caesar, and Vercingetorix's attempt to unite the Gauls against Roman invasion came too late. The wars paved the way for Julius Caesar to become the sole ruler of the Roman Republic.
Great St Bernard Pass
The pass had entered history with the Gallic invasion of 390 BC. The last Gallic invasion over it occurred in May, 1800, under the direction of the 30-year-old First Consul of the French Republic, Napoleon Bonaparte. An Austrian army of 140,000 men had laid siege to French-occupied Genoa on the west coast of northern Italy. Napoleon traversed the pass with 40,000 men and ⅓ of their heavy artillery sending another 20,000 over three other passes as a diversion, intending to strike the Austrian rear. The panicked Austrians were unable to assemble fast enough to meet the French en masse but rather in a piecemeal way in June 1800, and so were defeated first at the Battle of Montebello and then at the Battle of Marengo.