In heraldry, crossed keys are a powerful emblem of authority, guardianship, trust, and spiritual office. A key by itself represents access, custody, knowledge, and the power to open or close. When two keys are crossed, the symbolism becomes more formal and institutional, suggesting delegated authority, jurisdiction, and the responsibility to guard something precious. In Christian heraldry, the crossed keys are most famously associated with Saint Peter, to whom Christ gave “the keys of the kingdom of heaven,” making them a sign of apostolic authority, forgiveness, binding and loosing, and the government of the Church.

The best-known heraldic example is the arms of the Holy See, which display two crossed keys, one gold and one silver, bound together beneath the papal tiara or other papal insignia. These keys represent spiritual and temporal authority, as well as the power entrusted to Peter and his successors. The symbol also appears widely in the arms of dioceses, abbeys, churches, schools, and towns under the patronage of Saint Peter. For instance, the arms of York include keys in reference to Saint Peter, patron of York Minster, while many ecclesiastical examples are catalogued by Heraldry of the World.

As a charge, crossed keys may be shown addorsed, wards upward, wards outward, tied by a cord, or combined with a crown, mitre, sword, cross, or book. In civic heraldry, they can also represent fortified gates, civic custody, treasury, law, or the opening of trade routes. Useful background can be found through the College of Arms, Parker’s A Glossary of Terms Used in Heraldry, and the Heraldry Society. In coats of arms, crossed keys remain a dignified sign of sacred authority, entrusted responsibility, and guarded access.