She was the first-ever Queen of England to rule in her own right, but to her critics, Mary I of England has long been known only as “Bloody Mary.”

This unfortunate nickname was thanks to her persecution of Protestant heretics, whom she burned at the stake in the hundreds. But is this a fair portrayal? Was she the bloodthirsty religious fanatic that posterity has bequeathed to us? While hundreds died under Mary’s reign, her dark legacy may have as much to do with the fact that she was a Catholic monarch succeeded by a Protestant Queen in a country that remained Protestant. History, as they say, is written by the victors.

During her five-year reign, Mary had over 300 religious dissenters burned at the stake in what are known as the Marian persecutions. It is a statistic which seems barbaric. But her own father, Henry VIII, executed 81 people for heresy. And her half-sister, Elizabeth I, also executed scores of people for their faith. So why is Mary’s name linked with religious persecution?

Being burned at the stake was typical punishment for heresy.

Protestants being burnt at the stake during the Reign of Queen Mary I. Bettmann Archive/Getty Images

First, it’s important to understand that heresy was considered by all of early modern Europe to be an infection of the body politic that had to be erased so as not to poison society at large. All over Europe, the punishment for heresy was not only death, but also the total destruction of the heretic’s corpse to prevent the use of their body parts for relics. Therefore, most heretics were burned and their ashes thrown into the river and Mary’s choice of burning was completely standard practice for the period.

Read more: 8 Things You Might Not Know about Mary I

Her sister, Elizabeth I, was a little more savvy: in her reign those convicted of practicing Catholicism by training as priests or sheltering them were convicted as traitors and punished accordingly, by being hanged and quartered. The idea behind the different crimes was that, while people could dispute religious belief, no one could ever possibly agree that treason was permissible.

If one person can be held responsible for Mary’s reputation, however, it is the Protestant “martyrologist,” John Foxe. His bestselling work, The Actes and Monuments, better known as Foxe’s Book of Martyrs, was a detailed account of each and every martyr who died for his or her faith under the Catholic Church. It was first published in 1563, and went through four editions in Foxe’s lifetime alone, testament to its popularity.

The 1555 execution of Bishop Nicholas Ridley and Father Hugh Latimer, as depicted in the "Book of Martyrs" by John Foxe. Fototeca Gilardi/Getty Images

Although the work covered the early Christian martyrs, the medieval Inquisition, and the suppressed Lollard heresy, it was the persecutions under Mary I that got, and still receive, the most attention. This was partly due to the custom-made, highly detailed woodcuts depicting the gruesome torture and burning of Protestant martyrs, surrounded by flames. In the first, 1563 edition, 30 out of the 57 illustrations depict executions under Mary's reign.

Read more: How Henry VIII's Divorce Led to Reformation

The power of Foxe’s work arose also because of the intensely poignant way in which those martyrs were alleged to have gone to their fates. Whether his sources were accurate or not (and many believe they were not always entirely accurate), it is hard to not feel emotion at this typical account of some of the early Marian martyrs, the bishops Hugh Latimer and Nicholas Ridley:

“Then brought they a fagot kindled with fyre, and layd the same downe at D[octor]. Ridleyes feete. To whom M. Latymer spake in this maner: ‘Be of good comfort M[aster]. Ridley, and play the man: we shall this day lyght such a candle by Gods grace in England, as (I trust) shall neuer be put out.’”

As the fire took hold, Latimer was suffocated and died quickly, but poor Ridley was not so fortunate. The wood burned too furiously against his feet and so he writhed in agony and repeatedly cried out, “‘Lord haue mercy vpon me, intermedling this cry, let the fyre come vnto me, I cannot burne.’”

Protestant martyrs become powerful folklore.

First published five years after Mary’s death, Foxe’s work was a huge success. Printed as an enormous folio, the second edition was ordered to be installed in every cathedral church and church officials were told to place copies in their houses for the use of servants and visitors. But by the end of the 17th century Foxe’s work tended to be abbreviated to include only the most sensational episodes of torture and death. So the graphic accounts of pious Protestant martyrs submissively going to their painful ends at the hand of a “tyrant” became the folklore of the English Reformation.

Mary died at age 42 in 1558 during an influenza epidemic (although she had also been suffering from abdominal pain and may have had uterine or ovarian cancer). Her half-sister, Elizabeth, succeeded her as a Protestant monarch and England remained Protestant. Even if the various sects of that religion were then so at loggerheads that they plunged the kingdom into a civil war, Catholicism—or what they called “Popery”—was something they could all agree was worse than anything else.