At a minimum, he seems to have helped catalyze the process. Historian Emanuel Rostworowski describes him as a vital secretary-editor, who certainly participated in related discussions and influenced both Potocki and the king, and calls Piattoli's quarters in the Royal Palace a “creche” of the constitution. Piattoli was, finally, involved in the final preparations for the vote that took place during the Sejm session on May 3. Later that month he became a founder of the Friends of the Constitution. He was active in various political causes and worked closely with other key figures in Poland such as Hugo Kołłątaj. He became a trusted adviser to Dorothea von Medem, Duchess of Courland. He supported reforms to improve the status of the burghers and Jews. Final years During the War in Defence of the Constitution in 1792, Piattoli found himself on another diplomatic mission to Dresden, where he stayed after the Commonwealth's defeat at the hands of Imperial Russia resulted in the Second Partition of Poland. In Dresden and nearby Leipzig, Piattoli was active in the circles of Polish patriotic emigres, who included Potocki and Kolłątaj. In 1793 he officially parted ways with Poniatowski, receiving a letter in which he was discharged from his service. In 1794 he was involved in the preparations for the Kościuszko Insurrection against Russian influence, and in negotiations with the newly republican France, in which Polish reformists proposed an alliance with France, promising to turn Poland into a second republic in Europe. At the same time, he was involved in much more conservative negotiations with Russians. In July 1794 he and several other activists were exiled from Leipzig, and Piattoli was soon arrested by the Austrian authorities. After the failure of the Kościuszko Insurrection later in 1794, many prisoners were set free, but Piattoli was kept imprisoned, together with Kołłątaj, as the Russian authorities insisted that the two were “extremely dangerous”. Hence, even after the final Partitions of the Polish–Lithuanian Commonwealth in 1795, Piattoli was kept interned in Prague by the Austrian Empire authorities until 1800, despite requests for his release from Poniatowski and even Napoleon Bonaparte. His release in 1800 seems to have been the result of efforts of the Czartoryski family and Duchess Dorothea. After his release he returned to Dorothea's Courland court, where he served as a tutor for her daughter. Around 1803 he began cooperating with Adam Jerzy Czartoryski, who was now