The College of Arms is reincorporated by Royal charter signed by Queen Mary I of England and King Philip II of Spain.

The College of Arms is a royal corporation consisting of professional officers of arms, with jurisdiction over England, Wales, Northern Ireland, and some Commonwealth realms. The heralds are appointed by the British Sovereign and are delegated authority to act on behalf of the Crown in all matters of heraldry, the granting of new coats of arms, genealogical research, and the recording of pedigrees. The College is also the official body responsible for matters relating to the flying of flags on land, and it maintains the official registers of flags and other national symbols. Though a part of the Royal Household of the United Kingdom, the College is self-financed, unsupported by any public funds.

A royal charter is a formal grant issued by a monarch under royal prerogative as letters patent. Historically, they have been used to promulgate public laws, the most famous example being the English Magna Carta of 1215, but since the 14th century have only been used in place of private acts to grant a right or power to an individual or a body corporate. They were, and are still, used to establish significant organisations such as boroughs, universities and learned societies, and were historically used to establish companies.

Mary I, also known as Mary Tudor, was Queen of England and Ireland from July 1553 and Queen of Spain as the wife of King Philip II from January 1556 until her death in 1558. She made vigorous attempts to reverse the English Reformation, which had begun during the reign of her father, King Henry VIII. Her attempt to restore to the Church the property confiscated in the previous two reigns was largely thwarted by Parliament but, during her five-year reign, more than 280 religious dissenters were burned at the stake in what became known as the Marian persecutions, leading later commentators to label her "Bloody Mary".