The document conserved in the State Archives of Modena represents an essential moment in the history of the Este family: the attainment of the ducal dignity over Modena and Reggio, as well as the title of Earl over Rovigo and Comacchio and the recognition of the domains of Garfagnana, the elevation to Duke was granted to him by Emperor Frederick III of Habsburg.
We know the date of this document – 18 May 1452 – when the Emperor stayed in Ferrara again after his stay in Rome, where himself was crowned King of the Holy Roman Empire by Pope Nicholas V on 19 March of the same year. The hospitality, gifts and generosity that Borso reserved for the Emperor during his first stopover ensured his presence also during the return journey, creating the occasion to elevate Borso from the dignity of Marquis to that of Duke. Thus on Ascension Day after the solemn mass, the day continued with the investiture ceremony. This took place outdoors, on a richly decorated stage, at the Rigobello Tower and ended in the Cathedral, where the Duke took the loyalty oath.
The certificate shows two coats of arms in the centre, corresponding to the ducal and comital investiture. The shield on the left depicts the ducal investiture over Modena and Reggio, and is divided into four parts: the first and fourth quadrants show the two-headed black eagle with crown on a golden field, while the second and third quadrants show the golden fleurs-de-lis of France already granted by King Charles VII. A small shield with a white eagle is inserted in the centre. The coat of arms on the right instead represents the comital investiture over Rovigo and Comacchio, in which the crowned double-headed eagle is divided in half: on one side painted black on a gold field and painted white on a blue background. At the base of the two insignia are polychrome floral motifs embellished with gold buttons.
Unfortunately, there are only a few traces of the hanging seal of Emperor Frederick III in the lower part of the certificate.
The document represents a fundamental milestone in the history of the Este dynasty and, thanks to the new dignity achieved, Borso undertook a series of institutional reforms aimed at consolidating the power he had obtained and initiated the policy of magnificence that characterised his rule.
