He was afterwards appointed the prince's envoy at Paris, where he remained till the decree of Napoleon, forbidding all persons born on the left side of the Rhine to serve any other state than France, compelled him to resign his office (IS'I).
From 1816 to 1818 he was Luxemburg envoy at the German diet, but was recalled, at the instance of Metternich, owing to his too independent advocacy of state constitutions.
In 1864 he went as Hessian envoy to Vienna, retiring in 1872 when the post was abolished.
About this time Maximilian's ally, Ludovico of Milan, was taken prisoner by Louis XII., king of France, and Maximilian was again compelled to ask the diet for help. An elaborate scheme for raising an army was agreed to, and in return a council of regency (Reichsregiment) was established, which amounted, in the words of a Venetian envoy, to a deposition of the king.
It excited the admiration of Gonzales Clavijo, the Spanish envoy, when he passed through it on his way to visit the court of Timur at Samarkand (Clavijo, Historia del gran Tamorlan, p. 84); and Cardinal Bessarion, who was a native of the place, in the latter part of his life, when the city had passed into the hands of the Mahommedans, and he was himself a dignitary of the Roman Church, so little forgot the impression it had made upon him that he wrote a work entitled "The Praise of Trebizond" ('E-yac c uLovTpaire oiivros), which exists in manuscript at Venice.