Pope Gregory III
The custom of giving the rose supplanted the ancient practice of sending Catholic rulers the Golden Keys from St. Peter's Confessional, a custom introduced either by Pope Gregory II (716) or Pope Gregory III (740). A certain analogy exists between the rose and the keys: both are of pure gold blessed and bestowed by the pope upon illustrious Catholics, and also, both are somewhat reminiscent of a reliquary—the rose contains musk and balsam, the keys are filings from the Chair of St. Peter.