Sept 1798-May 1800 Joined the Maltese rebellion against French rule and was with the insurgents in besieging Valletta Cottonera, Floriana, and Fort Manoel. On the nights of Thursday 10 January and Friday 11 January 1799, Fabri took part in the abortive attempts to capture Valletta by a coup de main. The insurgents, with Fabri at their head, had gathered at Marsamxetto with the intention of entering Valletta through that gate. Subsequently Fabri, took part in the three assaults on the Cottonera in August 1799.
1 June 1799 Left on a service to the city of Palermo.
Malta 26 May 1800 Assistant Surgeon Maltese Light Infantry.
Brig-Gen Thomas Graham in a letter dated Gudja 26 May 1800, addressed to Acting Surgeon P Campbell Maltese Battalion stated,
I have appointed Mr Fabri to act as assistant surgeon to the Maltese Battalion of which you will acquaint Maj James Weir, and that of which a hospital to be established as soon as possible at Gudja, many of the recruits being ill and no place to put them in.
Malta 24 Aug 1801 Appointed Ensign Maltese Light Infantry (also known as Il Battalion Maltese di Sua Maesta Brittanica). He was succeeded by Assistant Surgeon Giuseppe Camilleri.
Malta 12 June–18 June 1802 Accompanied the invalids of the different foreign regiments to Leghorn.
Malta Jan–July 1803 Superintended the recruits in the country.
Malta Sept 1803 Captain Maltese Provincial Battalion. Was on duty at Fort Manoel, Cottonera, Citta Vecchia, and Fort Ricasoli.
9 May 1804 Received his first payment of £43 4s 6d in prize money from the proceeds of the property captured in Malta on 4 September 1800. This was equivalent to that paid out to a lieutenant and ensign in the infantry.
13 Aug 1804 Received his second payment of £14 1s 0d in prize money from the proceeds of the property captured on the island of Malta on 4 September 1800.
Malta Sept 1807–Dec 1807 Commanded No 5 Coy Maltese Provincial Battalion at Fort Manoel and Fort Tigne, and formed part of the guard for the French prisoners of war.
Malta Feb 1808–Apr 1808 Captain Maltese Provincial Battalion serving at Fort Chambray Gozo.
Malta June 1810–Dec 1811 Captain Maltese Provincial Battalion serving at Fort Chambray Gozo.
Malta 25 Dec 1811–Feb 1817 Reduced on to the supernumerary list.
May–Aug 1813 Gave his services gratis during the outbreak of the plague in Malta.