Among his measures, the urban renovation of Modena and the construction of the Via Vandelli, connecting the city to the Tuscan Duchy of Massa and Carrara (belonging to his daughter-in-law Maria Teresa Cybo-Malaspina and destined to be incorporated into the Este States), and to the Mediterranean Sea.

Previously he had already turned to the court of Great Britain for advice and help: King George II was a distant maternal cousin of his and Francesco looked to him as a sort of head of the family given the shared ancestral origins of the two dynasties from the House of Welf.

In 1763, despite the harsh opposition of Ercole Rinaldo, the two families agreed to simply replace the name of Leopold with that of his next junior brother, Archduke Ferdinand Karl of Habsburg-Lorraine, who had not yet been born at the time of the signing of the treaties and was four years younger than his betrothed.

In January 1771 the Perpetual Diet of Regensburg ratified Ferdinand's future investiture and, in October, Maria Beatrice and he finally got married in Milan, thus giving rise to the new House of Austria-Este.

Francesco III ceded to the archduke the post of governor of Milan and the new archducal couple settled in the Lombard capital where they lived the next about 25 years producing a large offspring of ten children.