Queen Mary I grants a royal charter to Derby School, as a grammar school for boys in Derby, England.

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 (great charter) 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 (with municipal charters), universities and learned societies.

Charters should be distinguished from royal warrants of appointment, grants of arms and other forms of letters patent, such as those granting an organisation the right to use the word "royal" in their name or granting city status, which do not have legislative effect. The British monarchy has issued over 1,000 royal charters. Of these about 750 remain in existence.

The earliest charter recorded on the UK government's list was granted to the University of Cambridge by Henry III of England in 1231, although older charters are known to have existed including to the Worshipful Company of Weavers in England in 1150 and to the town of Tain in Scotland in 1066. Charters continue to be issued by the British Crown, a recent example being that awarded to The Chartered Institute of Ergonomics and Human Factors, in 2014.

Mary I (18 February 1516 – 17 November 1558), also known as Mary Tudor, and as "Bloody Mary" by her Protestant opponents, was Queen of England and Ireland from July 1553 until her death in 1558. She is best known for her vigorous attempt to reverse the English Reformation, which had begun during the reign of her father, 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, Mary had over 280 religious dissenters burned at the stake in the Marian persecutions.

Mary was the only child of Henry VIII by his first wife, Catherine of Aragon, to survive to adulthood. Her younger half-brother, Edward VI, succeeded their father in 1547 at the age of nine. When Edward became mortally ill in 1553, he attempted to remove Mary from the line of succession because he supposed, correctly, that she would reverse the Protestant reforms that had taken place during his reign. Upon his death, leading politicians proclaimed Lady Jane Grey as queen. Mary speedily assembled a force in East Anglia and deposed Jane, who was ultimately beheaded. Mary was—excluding the disputed reigns of Jane and the Empress Matilda—the first queen regnant of England. In July 1554, Mary married Philip of Spain, becoming queen consort of Habsburg Spain on his accession in January 1556.

After Mary's death in 1558, her re-establishment of Roman Catholicism was reversed by her younger half-sister and successor, Elizabeth I.