On the withdrawal of the British legation from Paris Maret went on a mission to London, where he had a favourable interview with Pitt on the 2nd of December 1792.
In 1841 he entered the diplomatic service as secretary of legation in Russia, but resigned his post within three months.
At a later period he was councillor of legation in the Austrian embassy at the Frankfort diet, but in 1818 he returned to Vienna.
In 1854 he was appointed secretary of legation; but the aggressive ultramontanism of the Curia became increasingly intolerable to his overwrought nature, and in 1856 he was transferred, at his own request, as secretary of legation to Dresden.
Although the legation of Britain lasted as a rule only three years, Agricola held the post for at least seven and succeeded in reconciling the inhabitants to Roman rule and inducing them to adopt the customs and civilization of their conquerors.
To accompany, in the capacity of theologian, the papal legation sent to France soon after the murder of Henry III.
Wolsey, then engaged in beginning his reform of the English church, procured that he himself should be joined to the legation as senior legate; thus the Italian, who arrived in England on the 23rd of July 1518, held a subordinate position and his special legatine faculties were suspended.
The Greek Orthodox Catholics are represented by Russians, who reside in northern Persia; they have a church at the Russian legation in Teheran, and another at the Russian consulate in Tabriz.
After a diplomatic training in the legation at Rome he learned the practice of administration as intendente of Concepcion, and from 1871 to 1876 was minister of war and marine under Errazuriz.
In 1864 he entered the chancellery of the minister for foreign affairs at St Petersburg, and was soon afterwards attached to the Russian legation at Stuttgart, where he attracted the notice of Queen Olga of Wurttemberg.