Late in the summer of 1805, the Army of England, which Napoleon hoped to put across the English Channel to invade England, stood at readiness at the Channel ports, as it had the previous year. A coalition of Austria, Russia, and some of the German states, bankrolled by England, gathered to make a thrust at Strasbourg.
Napoleon liked a gamble, but even he was probably uncomfortable with spinning the roulette wheel and putting all his chips on the double zero of a cross-Channel invasion. So having some slow-moving enemy armies on the other side of Europe must have been a relief. He turned the Army of England around and sent 200,000 men east.
They moved with incredible speed, and were masked by a splendid deception operation, and in 20 days they were crossing the Rhine. In early October they were at the Danube, to the confusion and shock of the Austrian army.
Napoleon had accurately predicted where the Austrians would station themselves, and what route the lumbering Russian army under Kutuzov (ten days late because of a confusion between the Gregorian calendar, used in the West, and the Julian calendar used by the Orthodox Russians) would take in joining them.
He defeated the Austrians under Mack at Ulm (readers of War and Peace might remember the shabby figure saying: "You see before you the unfortunate General Mack!", though he actually said this to Napoleon), and then the Coalition army at Austerlitz, probably his greatest tactical victory.
The story is excitingly told by Alistair Horne in How Far from Austerlitz, Napoleon 1805-1815, and if you want to get up to speed on Napoleon's military career in an entertaining way, there are few better. Horne has written a number of pleasing military histories, mostly dealing with the encounters between France and Germany in their three wars--Austerlitz then forms the first of these, for it is during this period that Germany really starts to get it together as a military power.
Aside from clearly delineating the strategy and operations of the wars, Horne gives us the required illuminating anecdotes. Napoleon was
an indifferent horseman (Odeblen says scathingly, 'Napoleon rode like a butcher.... Whilst galloping, his body rolled backwards and forwards and sideways') and was thrown more than once
not too surprising for a former artilleryman. Horne details the detail Napoleon went into to make his dispositions:
As soon as the site for Imperial Headquarters in the field had been decided, d'Albe would set up Napoleon's 'operations room', the centre-piece of which would be a vast map table of the theatre of war, so large that the Emperor and his topographer would often be forced to lie on it full length together. 'I have seen them more than once,' wrote Baron de Fain, the Cabinet archivist, '...interrupting each other by a sudden exclamation, right in the midst of their work, when their heads had come into collision.'
Though it covers the period 1805-1815, Horne sketches in Napoleon's early career, including Italy and Egypt, as well as Napoleon's fate after defeat. Highly recommended.
How Far from Austerlitz, Napoleon 1805-1815