The College of Arms still holds its charter from Mary I of England (and Philip of Spain, her consort). It was granted on July 18, 1554 and according to this 1805 history of the College and its Heralds, it was an uncomfortable situation:
The apology which the College would offer, could be no other, than that they had been under compulsion to do as the Duke of Northumberland and the council commanded: afterwards they had done as duty and inclination dictated. Mary accepted the excuse with some exceptions. She appeared so satisfied, that Thomas, Duke of Norfolk, having represented, as Earl Marshal, the intentions of the late King in favor of the heralds, of granting them Derby-house, she gave them a charter, dated at Hampton-court, July 18, 1554 (sic), of that mansion, to "enable them to assemble together, and consult, and agree amongst themselves, for the " good of their faculty, and that the records and rolls might be more safely and conveniently deposited."
According to the website for the College of Heralds, their functions have changed since the days of tournaments and jousting knights:
Although many of the ceremonial duties of heralds have disappeared they still carry out and organize under the Earl Marshal, certain extremely ancient and splendid ceremonies. In June each year at Windsor Castle is held the procession and service of the Sovereign and Knights Companion of the Order of the Garter. The State Opening of Parliament, usually in November, is another magnificent ceremony. The Earl Marshal, the Duke of Norfolk, is one of the two Great Officers of State and the office is hereditary in his family. He has particular powers of supervision over the heralds and the College of Arms.
The arrangement of State funerals and the monarch's Coronation in Westminster Abbey fall under the jurisdiction of the Earl Marshal, and the heralds have a role in their organization.
At all these ceremonies the heralds wear their highly distinctive medieval uniform, the tabard. This is a coat embroidered on its front, back and sleeves with the Royal Arms.
And the same page concludes with reference to this date, when Mary and Philip granted the charter:
The Duke of Norfolk, currently Edward William Fitzalan-Howard, the 18th, is the Earl Marshal and in charge of the College of Arms and thus in charge of heraldry in England and Wales, approving each coat of arms granted, including this one for the Duke and Duchess of Cambridge. The Norfolks are, of course, one of the old recusant families, remaining Catholic throughout the centuries.