The whole campaign of Napoleon was quiet desperate. He had collected his old burned out veterans and inexperienced youngsters. His army was not well trained. His staff has past its top and N himself was not at a very good condition.

N had to start a fight. He had to win before the joined forces of Russia, Austria and Prussia would appear. Even then he had little chance to win.

The Allied forces were not much better. Wellington had some elite phalanx (or musketeers ) but most of his soldiers were low quality.

Wellington's army was good in defense and so was their commander. Blücher's army was good in offensive and so was Blücher, too.

Both leaders promised to help each other in case Napoleon attacks.

N's plan was simple and good: Attack Blücher before he can join Wellington! At the battle of Ligny he could beat the Prussians. Wellington did not come in time. If N had attacked Wellington instead, Blücher had been faster to help Wellington probably.

So the Prussians had to run and N could turn to Wellington. Now something happened that was not according to the plan. Blücher did not retreat to his base in the east. He turned and tried to reach W. Weather helped him.

The battle of Waterloo (or Belle Alliance) was not Napoleon’s masterpiece. But it is funny: if you read the comments you see that Napoleon and his generals made one mistake after the other while Wellington choose a brilliant defensive position. However if you look at the numbers losses at both sides were equal. It is always good to write comments after the battle.

In the afternoon Wellington’s troops were exhausted and Napoleon was about to win. The attack of the Prussians changed the battle.

So there are many factors for the defeat: Napoleon’s weakness, the rain, Wellington’s stableness …. But the most important factor was Blücher’s maneuver and his will to beat Napoleon after the defeat at Ligny.

But this interpretation may be a bit German.