 He then served as Spanish ambassador to Russia under Emperor Peter II (December 1726 to 1730), taking with him Ricardo Wall (1694–1777), later a minister in the Spanish government.During his time in Russia he was made a Knight of the Russian Order of Saint Andrew (28 March 1728), a Knight of the Russian Order of Saint Alexander Nevsky and a Knight of the Garter (by James Stuart on 3 April 1727).From 1730 to 1733 Stuart was ambassador in Vienna, then from 1733 to his death in 1738 ambassador to the "recovered" Kingdom of Naples (taking Wall with him again on both missions).