Having grown up amid war and hardship, Mercurino di Gattinara, like many others, responded to the chaos by trying to impose order on his adult world. The deliberate nature of his decision-making revealed itself in his childhood. A belief in the hand of destiny led him to view every event in his life as fitting into a larger scheme, not only in the trajectory of his own personal narrative but also in the plane of sacred history. The confidence that fate had selected him for a larger purpose enabled and developed another important aspect of his temperament: his opposition to authority. As he resisted the pressure of family, tradition, royal and ecclesiastical forces, so he also weakened the opposition to his own power. This account of his life, combined with his autobiography, reveals his energy and sense of purpose. Ambition dominated his character and directed his course as a ruling passion.

The town of Gattinara, the most likely birthplace of Mercurino, suffered a tumultuous history in the fourteenth and early fifteenth centuries. The wars between the Francophone dukes of Savoy, the Visconti of Milan and the marquises of Montferrat took their toll on the small city. In 1426 Amedeo VIII of Savoy took definitive possession of the commune and appointed a podestà as representative of the duchy. The noble families, including the Arborio, also submitted to the dukes.