In the usurpation of Richard II’s throne in 1399 and the establishment of the House of Lancaster, much credit is given to Henry IV (obviously) and his father, John of Gaunt. But it’s worth recognizing that without the wealth and inheritance of Blanche of Lancaster, neither would have been as well-positioned to challenge their Plantagenet cousins.

Blanche was born in March 1347 to Henry of Grosmont, Duke of Lancaster and Isabel de Beaumont. She was the youngest of two daughters, her elder sister, Maud, having been born in 1339. Given the gap between the two girls’ birth and the lack of subsequent children, including a male heir, it’s clear that the couple suffered from fertility issues, a situation that led to their daughters growing up to be extremely desirable heiresses on the English marriage market.

Blanche and Maud would likely not have been terribly close given that Maud was married while still a child to Ralph Stafford, who died young. Her second marriage, contracted in 1352, was to William V, Count of Holland, Zeeland and Hainaut and sent her abroad.

In 1359, when Blanche was about 12, she married King Edward III’s third son, John of Gaunt, Earl of Richmond. The match was mutually beneficial, garnering Blanche strong royal connections and lending John the fortune he needed to build a career. Around this time Blanche’s father, Henry, participated in one of the great English thrusts of the Hundred Years War, the Rheims campaign in 1359-1360. Shortly after his return to England he fell ill and died on March 23, 1361.

The death was significant because inheritance through women was always made more complicated. His estate was divided between his two daughters, which essentially meant between their two husbands. Maud’s husband had been confined for insanity since 1358 and was a bit of a non-entity, but the earldom of Leicester passed to her. Fortuitously for John, she died the following year, in 1362, which meant the entirety of the Lancastrian inheritance went to Blanche.

By the end of 1362, John and Blanche were styled the Duke and Duchess of Lancaster, and the wealth of those associated lands positioned John to become one of the wealthiest men in England after his older brother, the Prince of Wales (aka the “Black Prince”).

By 1362, Blanche had given birth to one child, a daughter named Philippa after Edward III’s queen, Philippa of Hainaut. A son, named John after his father, would be born between 1362 and 1364, but he died young. A second daughter, Elizabeth, was born in 1364. Two more sons, Edward and John, were born in 1365 and 1366, and died in infancy, creating a dynamic that indicated Blanche might fall into the same trap as her mother, a producer of daughters, but no living sons.

Henry was born on April 3, 1367 at Bolingbroke castle, lending him the name by which he was first known, Henry of Bolingbroke. He was followed by one more sister, Isabel, in 1368 who also died in infancy.

Blanche died on September 22, 1368 at Tutbury Castle, aged 21, quite possibly from the Black Death which had swept England that summer. John was overseas at the time and their three children, Philippa, Elizabeth and Henry, were moved to the household of a relative for the next few years.

After Blanche’s death, Geoffrey Chaucer wrote “The Book of the Duchess,” which is believed to have been written in her honor. There are multiple references to “white” in the text, a play off of “Blanche,” as well as “long castle” for “Lancaster,” and “rhyche hill” for “Richmond,” John’s title when they married.

For all that Blanche was young when she died, she had been an incredibly admired woman in England for her beauty, decorum and piety, and she was well-liked by the extended Plantagenet family. John appears to have sincerely mourned her, which brings up another point: the extent to which this was a love match. The marriage was certainly not inspired by it given that it was arranged by their families and both profited from it too much, but it’s entirely possible that the two were well-acquainted in childhood and also in favor. It’s also possible that they grew to love another over the course of their nine-year marriage.

There’s a belief that Chaucer’s book was meant to point out John’s mourning of his wife had grown excessive, which, if true, is further indication that he had loved her. For the 31 years that John lived on, he commemorated Blanche’s death annually and, upon his own death, founded a joint chantry to continue to honor her.

Notably, despite two  more marriages, John chose to be buried next to her in an alabaster effigy that showed their hands intertwined. However, this can be taken a number of different ways. Blanche was the mother of his heir, his first wife and, as we have established, the source of the base of his fortune. It may have also felt like the correct place for him to be buried, though the joined hands, which was not the norm, indicates there was emotion behind it.

Three years after her death he married Constance of Castile and attempted to help her regain her inheritance in Castile – a move I’ve just described as altruistic, but naturally meant that he was vying for a throne of his own. They had one daughter, Katherine of Lancaster, who ended up marrying King Henry III of Castile. Katherine of Aragon, Henry VIII’s first wife, is descended from and named after her.

When Constance died in 1394 John went on to marry his long-time mistress, Katherine Swynford. They already had four children – John, Thomas, Henry and Joan Beaufort – who were legitimized by an act of Parliament and were strong supporters of their older half-brother, Henry of Bolingbroke.

It’s possible that Blanche knew Katherine given the uncertainty around Katherine’s formative years, as well as when exactly she began caring for the Lancaster children. If they did know one another, it’s considered unlikely that an affair started until well after Blanche’s death.

As for Blanche’s son, he would go on to take the throne of England in 1399 and become King Henry IV. Given that he was an infant when she died, Henry would have had no way of remembering his mother, but did honor her memory by naming one of his daughters after her. That Blanche would go to marry Louis III, Elector of Palatine.

The incredibly elaborate tomb that John designed and commissioned for himself and Blanche was destroyed in the Great Fire of London in 1666. The below drawing captures what it once looked like: