To contextualize: He officially disapproved of Napoleon's Spanish initiative, which resulted in the Peninsular War beginning in 1808. (But he pushed Napoleon to wage war againt spain) At the Congress of Erfurt in September–October 1808, Talleyrand secretly counseled Tsar Alexander (crossing Napoleon again).

After his resignation in 1807 from the ministry, Talleyrand began to accept bribes from hostile powers (mainly Austria, but also Russia), to betray Napoleon's secrets.

Talleyrand and Joseph Fouché, who were typically enemies in both politics and the salons, had a rapprochement in late 1808 and entered into discussions over the imperial line of succession.

Napoleon had yet to address this matter and the two men knew that without a legitimate heir a struggle for power would erupt in the wake of Napoleon's death.

Talleyrand started to spread the news that Napoleon had died in the hope of creating a coup d'ètat

Napoleon (While in Spain) received word of their actions and rushed back to Paris to stop the Talleyrand's action.

This perception caused the famous dressing down of Talleyrand in front of Napoleon's marshals, during which Napoleon famously claimed that he could "break him like a glass, but it's not worth the trouble" and added with a scatological tone that Talleyrand was "shit in a silk stocking" to which the minister Talleyrand coldly retorted, once Napoleon had left, "Pity that so great a man should have been so badly brought up!"