St. Adeodatus I
Deusdedit · 615 – 618
The first pope to use lead seals on papal documents, a practice that endured for centuries.
Deusdedit (meaning 'God has given') was a Roman priest who became pope in 615. He showed particular concern for the secular clergy rather than monks, and he cared for victims of a devastating earthquake and plague that struck Rome in 618. He is the first pope known to have used lead seals (bullae) to authenticate papal documents.
Why He Matters
Adeodatus I cared for Rome through plague and earthquake. His practical compassion and his innovation in papal documentation both shaped how the papacy functioned for centuries afterward.