Antonio was the elder son of Louis I of Monaco and Catherine Charlotte de Gramont.

He "completed the fortifications of the Rock of Monaco, constructed the Oreillon and the Fort Antoine.

"[1] He constructed the Rampe Major in 1714; this was an improved road connecting La Condamine to the "platform of the peninsula.

"[1] The Oreillon tower commanding the ramp leading to the Palais Princier[2] was constructed between 1707 and 1708.

[1] On 13 June 1688, Antonio married Marie de Lorraine, "Mademoiselle d'Armagnac" (1674–1724), a daughter of Louis, Count of Armagnac.