Francesco I d'Este

Francesco I d'Este
Duke of Modena and Reggio
Francesco I d'Este by Diego Velázquez
Born	(1610-09-06)6 September 1610 Modena
Died	14 October 1658(1658-10-14) (aged 48) Santhià, Vercelli
Spouse	Maria Caterina Farnese Vittoria Farnese Lucrezia Barberini
Issue	Alfonso, Hereditary Prince of Modena Alfonso IV, Duke of Modena Isabella, Duchess of Parma Rinaldo, Duke of Modena Maria, Duchess of Parma
House	House of Este
Father	Alfonso III d'Este, Duke of Modena
Mother	Isabella of Savoy

Francesco I d'Este (6 September 1610 – 14 October 1658) was Duke of Modena and Reggio from 1629 until his death. The eldest son of Alfonso III d'Este, he became reigning duke after his father's abdication.

The pestilence of 1630–1631 killed 70% of Modena's inhabitants. After the outbreak of the Thirty Years' War he sided with Spain and invaded the duchy of Parma, but upon visiting to Spain to claim his reward, he could only acquire Correggio by a payment of 230,000 florins.

Later followed the First War of Castro, in which Francesco's Modena joined Venice and Florence and sided with the Dukes of Parma against Barberini Pope Urban VIII, aiming to reconquer Ferrara. The war ended without any particular gain for the Modenese. As again no help had come from Spain, Francesco allied with France through the intercession of Cardinal Mazarin. When he however failed to conquer Cremona, and as the situation of the Thirty Years' War seemed to be favourable for Spain, the Duke sought for an agreement with the latter. He returned to the service of France by marrying his son and heir Alfonso to Laura Martinozzi, Mazarin's niece.

After successful resistance to a Spanish invasion from their territories in Milan, he fought alongside France and Savoy, conquering Alessandria and Valenza in 1656–1657 with the help of his son. In 1658 he conquered Mortara but, struck by malaria, died in Santhià soon later. After Maria's death in 1646, he married her sister Vittoria Farnese who died 1649.