 Empress Maria Theresia was satisfied with his performance to such an extent that in 1769 she gave him the important position of the Emperor's special envoy and plenipotentiary at the Court of St James's in London.In the following years he also accompanied Maria Theresia's son Joseph on his journeys to a number of European courts and cities.On 3 May 1781, Belgiojoso was admitted a Fellow of the Royal Society.