Marchese cultivated interests in history, archaeology, poetry and the Maltese language, and he was also a great patron, and collector of works of art.

Born on 12 September 1757, in Valletta, he was the fourth son of Cavaliere Giuseppe Isidoro Marchese and Serafina Marmier de Salins.

[2] On 12 January 1784, he married Anna Maria Camilleri Bianchi from Senglea,[1] with the nuptial mass celebrated by the Inquisitor Antonio Felice Zondadari in the chapel of the Holy Office, highlighting Marchese's respected position within Maltese society, and the Church.

On 8 March 1793, Emmanuel de Rohan-Polduc, Prince and 70th Grand Master of the Order of St. John, awarded him the title of Count of Maimon.

He also took a keen interest in Maltese artists, such as Michele Busuttil and Giuseppe Grech,[3] and commissioned art from painters popular in Malta, like Anton Shranz.

[6] The contents of this lost library included volumes on classical and contemporary literature and poetry, political theory, history books, the lives of saints and popes, travelogues, museum periodicals, illustrated guides to museums and cities, works on the lives of artists, artist monologues, and books about prints and engravers which Marchese often referred to when giving attributions to the prints he purchased.

His register of purchases, titled 'Primo Costo',[11] is an invaluable document, detailing over 85 paintings, including religious works, landscapes, and still lifes.

[15] The hall's centerpiece is the polyptych of St. Paul, Malta's oldest altar painting, commissioned from the Catalan school of Lluís Borrassà.