Mary Boleyn was the sister of the more famous Anne Boleyn. As such, she is usually mentioned in the numerous biographies that have been written about Anne, but never in any substantial detail. Mary, unlike Anne, has been claimed to be the mistress of two kings – Francis I of France and Henry VIII of England. She was born sometime between 1499 and 1508. A popular but unverifiable legend suggests that Mary was considered the prettier of the two sisters while Anne was witty, intelligent and charismatic. Mary was married twice, first to William Carey, and second to William Stafford. She died in her early forties in 1543.
Areas of disputed historical accuracy include the following:
- Birth order and early lives of the siblings. Many histories, including Eric Ives's biography of Anne Boleyn, present evidence that Mary was the elder sister, and the eldest of the Boleyn children, whereas The Other Boleyn Girl presents Mary as the youngest of her siblings. George is portrayed as being born in 1503, Anne in 1507, and Mary in 1508. However, most historians agree Mary was born around 1500, Anne about 1501 and George about 1507, so that Anne was the younger of the two sisters. Mary's grandson knew she was the eldest, according to the claim he made to his great-grandfather's titles, which he based on Mary having been the eldest, and which was certainly believed by his cousin, Elizabeth I, who offered him the titles in 1596.
- Sexuality of George Boleyn. The book depicts George Boleyn as being homosexual, in love with Francis Weston, but sexually attracted to his sister Anne and willing to commit incest with her. American academic Retha Warnicke postulated George Boleyn and his associates might have been homosexual, but no contemporary evidence supports the theory. However, George Cavendish in "Metrical Visions" wrote that he was a notorious seducer of women. Also, no contemporary records mention Anne Boleyn giving birth to a deformed foetus, which Gregory depicts and the characters interpret as possible evidence of incest.
- Paternity of Mary Boleyn's children. It has long been rumoured that Henry VIII fathered one or both of Mary Boleyn's children, originating from a report made in 1531 by an anti-Boleyn prior and Catherine of Aragon adherent, who had never seen the boy. There is some debate, with Sally Varloe, G. W. Bernard (author of The King's Reformation), and Joanna Denny (author of Anne Boleyn: a new life of England's tragic Queen and Katherine Howard: a Tudor conspiracy) arguing that he may have been Henry Tudor's son. Some writers, such as Alison Weir, consider it unlikely that Henry Carey (Mary's son) was fathered by the King.
- Role of Thomas and Elizabeth Boleyn. The Other Boleyn Girl depicts Mary's parents as devoid of affection for their daughters, and eager to use both as sexual pawns for political gain. Sources such as Anne Boleyn by Marie-Louise Bruce (1972) suggest that Mary's parents did not encourage her sexual escapades and were horrified when she was sent home from France in disgrace.
- Anne Boleyn's wardship of Henry Carey. Anne Boleyn took on Mary's son as her ward after his father's death during an outbreak of sweating sickness and supplied him with an education at a respectable Cistercian monastery. This was a common practice in the Tudor nobility and one very similar to the situation faced by dozens of young aristocratic children, including Anne and Mary's cousin, Katherine Howard, who was raised by her grandmother when her father was penniless. Anne's actions are usually seen as kind by contemporaries and historians, but the novel presents it differently: Anne "steals" Mary's son the year after Henry VIII has made it clear that he intends to marry her, to make herself more politically attractive to the king. It is shown both as a cruel act and as an adoption in the modern sense, in which the child's caretakers are considered his legal and social parents. Actually, Anne secured Mary a highly respectable pension of £100 a year.
- Sexual experience of Mary Boleyn. Mary is depicted in The Other Boleyn Girl as a sexually inexperienced young girl when she begins her affair with the king. In fact, however, she acquired a reputation for promiscuity at the court of Francis I of France, who stated that he had known her "per una grandissima ribalda, infame sopra tutti [a great slut, infamous above all]." Although Francis called her "the English mare," and estimated how often he had ridden her, Mary was never one of his favored maitresse en titre. Due to her sexual laxness, she appears to have been recalled from the French court in 1519, shaming the Boleyn family. Genealogist Anthony Hoskins contradicts Mary Boleyn's reputation for having been sexually active at an early age; denies that Mary was extensively educated at the French court like her sister; and declares that "It is now established that it was Anne Boleyn, and not her sister Mary, who lived at the Flemish and French courts as a child," as if this fact had not been known for centuries. Hoskins further speculates that the French king's comments on Mary's reputation were not based on her early behaviour, claiming that he possibly had met her in 1520 at the Field of Cloth of Gold. In fact, both Mary and Anne spent time at the French court.
- Motivations and characterisation of Anne Boleyn. The Guardian described Anne as having been presented as "a scheming trollop," and expressed incredulity at such a characterisation. In The Other Boleyn Girl, Anne Boleyn is presented as cold, vindictive, ruthlessly ambitious, vain, and given to physical violence; this is not supported by contemporary accounts. She was certainly complex: highly intelligent, fluently bilingual, politically astute, artistically gifted, loyal to her family, generous to friends, and known for her charm and elegance, notwithstanding arrogance and a notorious temper when stressed. During her time abroad, she was reported to have been sweet and kind. Feminist scholars objected to Gregory's characterisation and praise Anne Boleyn as a feminist icon.
- Incest between Anne and George Boleyn. Historically, Anne Boleyn was charged by Henry's appointed officials of committing incest with her brother. The novel heavily implies but does not state that Anne, convinced that Henry VIII could not give her a healthy son, resorts to incest with her brother. Both the 2003 BBC production of The Other Boleyn Girl and the 2008 film with Natalie Portman depict the two attempting but not committing incest. None of the sources Gregory listed in her bibliography question Anne Boleyn's innocence. Gregory used two biographies of Anne, one by the American historian Retha Warnicke and another source by Marie-Louise Bruce (1972). Both these writers insisted that Anne was innocent, as did books by David Loades, Alison Weir, and Lacey Baldwin Smith that Gregory had used when researching the story. Gregory did not use Eric Ives's 1986 scholarly biography on Anne Boleyn, The Life and Death of Anne Boleyn: the Most Happy, in which Ives expounds the possible political motives for Anne Boleyn's fall. Ives describes Anne as an active and effective politician, and explains Anne's fall and execution as the result of minister Thomas Cromwell's determination to avoid a similar fate to that of Cardinal Thomas Wolsey. There is no evidence supporting Gregory's assertion that Anne had three miscarriages. Gregory ignores the argument, as stated in Eric Ives's biography of Anne Boleyn, that part of the reason Anne was executed was because of her political and religious leanings, which her brother shared and supported.