Montebello was well connected through his family. His cousin, Giuseppe Montebello (1713–1833), from Tarxien, was the son of Montebello's uncle, Peter, and a well-heeled merchant. He was "Capo di Casal Tarxien" (Head of Tarxien), elected by the gentry there to represent them in all administrative matters. During the French presence in Malta (1798), he was chosen to be part of the committee administering one of the twelve municipalities created by Napoleon, that which included Tarxien, Żejtun, Żabbar and Għaxaq. Only three months later, however, Montebello was very much involved in the organised resistance of the Maltese against the French between 1798 and 1800. As head of the local provisional government at Tarxien, he was appointed "capo battaglione" (battalion leader) with operational responsibilities around that locality. Together with others, he contributed financially to the two-year war effort, and also donated (on 24 December 1798) a considerable part of his wealth to procure wheat and other supplies from Sicily to ease the food shortage that ensued from the revolt. When the British provisionally took over the government of the Maltese islands instead of the French Republican Commission, Giuseppe was elected by the gentry at Tarxien (18 February 1799) to be head of their locality, and thus part of the National Congress created by the representative of the British provisional government, Alexander Ball. Later, Giuseppe was appointed "Logotenente di Governo" (Government Lieutenant) of Tarxien. Afterwards, when the British officially became lords of the land, and partitioned the Maltese islands into six districts, Giuseppe was appointed Deputy Lieutenant of the district comprising Tarxien, Paola, Żejtun, Żabbar, Gudja and Luqa (28 June 1815). Giuseppe's house at Tarxien, built by government funds as recompense for his share in the revolt, still stands unto this day, and is a tourist attraction.