On 3 September 1798, Gozitans rebelled against the French occupiers, and on 18 September Cassar was appointed head of the Government and Superintendent of the Island of Gozo.
The Maltese Congress of Mdina (ruled by the British) disapproved of Cassar's actions, and on 20 August 1801 the British appointed Emmanuele Vitale as Governor of Gozo instead of Cassar [REF].