During his time in St. Petersburg, La Harpe began to plan an uprising of the people of Vaud against the rule of Bern. La Harpe returned to Switzerland in 1794, in the midst of the French Revolution of 1787–1799, to seek support for his planned uprising; with support gathered, La Harpe continued to Paris, seeking French support to fight the control of Bern, publishing documents such as the "Essay on the Constitution of the Vaud". On 10 December 1797 he addressed the French Directory, stating that commitments made by the Duke of Savoy in treaties signed with Bern at Lausanne in 1564 were now the responsibility of the French and thus gave them the right to assist the people of Vaud against the Bernese.