Strengths of Napoleon's opponents
Allies remained united. They weren't deterred by Napoleon's offerings for peace. Link to international situation.
British General Wellington's generalship was excellent. Making good use of tactics, especially at Waterloo (18th June 1815), where he ordered the infantry to lie down when Fr. artillery fired.
Wellington + Blucher worked well together. Reinforcing point of Allied unity.
Victory at Waterloo for the Allies was a joint effort.
Furthermore Wellington + Blucher were in the thick of the battles during the Hundred days.
This can be contrasted with Napoleon's lack of involvement, link to Napoleon's weaknesses.
British army fought better than expected.
For instance they fought in 2 deep lines + used well trained infantry.
Coupled with Napoleon's poor generalship, Allied generalship arguably provides the key to Napoleon's defeat in 1815.
Weaknesses of Napoleon as a military leader
Napoleon lacked imagination in his military plans as time went on.
For instance he used a frontal attack at Waterloo.
Moreover Napoleon didn't act on advice given to him by his generals; who had fought Wellington during the Peninsular war. (1808-14)
Could be said Napoleon chose the wrong Generals for the 100 days Campaign. (1815)
Marshal Ney was cautious. Uncharacteristically for him, considering he was regarded as 'the bravest of the brave'.
In addition Grouchy was inexperienced in high command. Perhaps led to his mistake, which resulted in the Prussians flanking the French at Waterloo.
Davout, would have been a better choice.
Napoleon spent periods of time being inactive. Morning of 17th June 1815 for example.
Where he let Wellington escape from the clutches of Ney at Quatre-Bras + remained…