Coming from a strong academic background, Leonello brought significant unprecedented economic, political, and cultural changes to Ferrara right after he took over from Niccolò III. In May 1444, Leonello married Mary of Aragon who was at the age of 19, illegitimate daughter of King Alfonso V of Naples. The marriage was a political one. To ensure the political stability within Ferrara, Leonello remained neutral in the political affairs between Milan and Venice. However, Leonello had a much broader picture for Ferrara, expanding its authority and power in its area. After the death of Margherita Gonzaga, Leonello saw the opportunity of forming alliances with neighboring regions through kinship to strengthen its power. The victory of Alfonso V in Naples, the father of Mary of Aragon, acted as a catalyst for such a diplomatic marriage for Leonello and an opportunity for Ferrara.