Mary of Modena entered English court life as the Catholic wife of James, Duke of York, in 1673. She formed relationships with his daughters Mary and Anne while maintaining a Catholic household amid increasing political hostility. Repeated pregnancies and the deaths of young children marked the marriage. When James became king in 1685, she became queen consort and was crowned with him that April.

The birth of James Francis Edward in June 1688 transformed the succession by creating the prospect of another Catholic king. Opponents circulated the false story that a substitute infant had been brought into the birth chamber in a warming pan. The controversy strengthened resistance to James's government. When William of Orange invaded, Mary escaped to France with her son in December. Louis XIV gave the family refuge at Saint-Germain-en-Laye, where she maintained the exiled royal household and court connections.

After James's death in 1701, Mary represented her son's claims while he was still a minor, corresponded with supporters and helped sustain the Jacobite court. Her daughter Louisa Maria remained with her until dying of smallpox in 1712. The peace settlement of 1713 required her son to leave France, deepening Mary's isolation and financial difficulties. She divided her life between Saint-Germain and the convent at Chaillot, remaining close to its religious community. She died in 1718. Her responsibilities combined family care, religion and the support of a displaced dynasty.