Leonello's succession and subsequent marriage would also serve an important role in relations with neighbouring city-states. Previously, the House of Este owed a great debt to Gianfrancesco Gonzaga, the ruler of Mantua. Instead of having this debt paid monetarily, Gonzaga agreed to have his daughter Margarita marry Leonello, in exchange for Niccoló promising his daughter's line of descendants the position of lords in Ferrara. Hence, the two rulers sought to use the marriage of their children to both their advantages, by resolving the issue of debt and also improving their relationship with the other city-state. This was also advantageous for Leonello, as he was guaranteed political support from another ruler through his marriage.