Giulio was the third son of Count Fabio Visconti and Margharita Arese. The family was a side branch of the noble family of
Visconti of Milan, which can be traced back to Charlemagne. This line died out with him in the male line, since his marriage to Teresa Cusani, produced only one daughter. After the end of the
War of the Spanish Succession, he entered the service of the Habsburgs, the new masters of his homeland in the
Duchy of Milan. In 1726 he was appointed
Minister plenipotentiary of the Austrian Netherlands and thus the highest administrative officer under the governorship of
Archduchess Maria Elisabeth. During this time he was also entrusted with diplomatic missions to London. His promotion to the independent position of
Viceroy of Naples in 1733 can be interpreted as an indication of the satisfaction of the court in Vienna. His actual term of office there only lasted until 1734, when the Austrian troops and the administration had to vacate the country before the advancing Spanish troops led by
Charles of Bourbon. In a decree of Emperor Charles VI from June 18, 1738, he is described as Grandee of Spain, Knight of the Order of the Golden Fleece, Privy Councilor of State, General of the Artillery and Obersthofmeister of the Empress. == Sources ==