By the “union of Tudor and Stuart” I don’t mean that of England and Scotland, but rather the marriage that facilitated the eventual consolidation of power in James I in 1603 and the later formation of the concept of “Britain.” All of that was a long time in the making and it stemmed from the union of King James IV of Scotland and England’s Princess Margaret Tudor in 1503.

The alliance came together in the Treaty of Perpetual Peace signed on January 24, 1502 at Richmond Palace. The treaty was the first between the two countries in roughly 170 years and it ended what had become nearly two centuries of warfare – that said, it was England and Scotland, so even that two centuries needs to be put in the context of several more of bloody battles over sovereignty.

In 1502, Margaret’s father, Henry VII, had been on the throne for 17 years. His predecessor, Richard III, had made a name for himself in the late 1470s and 1480s by winning border wars against the Scottish and humiliating James IV’s father, James III. A generation before that, James III’s mother, Mary of Guelders, had helped the Lancastrians – from which the Tudors stemmed –  during the Wars of the Roses when Edward IV deposed Henry VI. And even before that, James I, had been held as a prisoner at the courts of Henry IV and Henry V before marrying a Beaufort and returning to Scotland.

It was a deeply intertwined history of, essentially, frenemies – two royal families who should have felt some kinship thanks to geography and yet too often were rivals who sought to keep the other in check by engaging in continental alliances.

More personally, the marriage of Margaret Tudor to James Stewart made a certain amount of sense. Two decades earlier, Margaret’s maternal aunt, Cecily of York, had nearly married him in a similar  treaty. The same agreement had also nearly brought around the union of James III and Margaret’s maternal grandmother, the widowed Elizabeth Woodville. In any event, the alliance with Scotland in the early 16th century helped to secure England’s borders as it transitioned from the era of the Wars of the Roses to a period of more continental engagement under the Tudors. It offered some assurance that the Stewarts would stop hosting the pretenders who challenged Henry VII’s throne, like Perkin Warbeck, the decade before.

Within three months of the treaty’s signing, Margaret’s older brother, Arthur Tudor, was dead and the new heir to the throne was her younger brother, Henry. Even still, the marriage moved forward. That December, James re-pledged his commitment to the peace at Glasgow Cathedral  and the following January, their proxy wedding was held at Richmond. From that point onward, Margaret was styled “Queen of Scotland.”

Festivities, however, came to a screeching halt a little more than two weeks later when Margaret’s mother, Elizabeth of York, died after giving birth to her last child at the Tower of London. In short order, Henry had lost his heir and his wife, and soon he was to lose his daughter, too. Margaret, 13, was without any maternal guidance in the last months before her departure, and so it was her paternal grandmother who stepped in, the formidable Margaret Beaufort, Countess of Richmond, who helped see her namesake across the finish line. And see her off she did, as Margaret bid her family goodbye that summer, making a long progress north where she was met by the Scottish court on August 1st.

In 1503 James was 30 and had garnered himself a reputation for being a bit of a womanizer. He had seven bastards to his name, the youngest of which had been born in the summer of 1502 to Isabel Stewart, the daughter of the Earl of Buchan. And shortly before that his court had been split over the issue of his seeming “love” for his mistress, Margaret Drummond – so much so that when she died in 1501 there were many who whispered it had been poison at the hand of jealous courtiers. Evidence suggests that at least half of the rumor was true since her two sisters who shared the same meal also died shortly thereafter of similar symptoms.

Likely James was fairly ambivalent about the marriage itself as he waited for Margaret to arrive, but he needed legitimate heirs and, frankly, Scotland couldn’t afford further war with England. After meeting on August 1, James returned to his bride three days later to comfort her when a fire broke out in the stables, killing her favorite horses. Three days after that, Margaret formally entered Edinburgh and the day after that, they were married at Holyrood Abbey. The next morning, per Scottish custom, James bestowed on Margaret Kilmarnock as a “morrowing gift.”

A month later, the couple began a progress of Margaret’s dower lands that included the young queen’s introduction to the castles, cities and towns that would become intimately familiar over the years. One such residence was Stirling Castle, however no one had apparently felt it right to warn Margaret that it was used to house her husband’s illegitimate children. What exactly her reaction to the situation was, we don’t know, but there are enough contextual clues to assume Margaret, at the very least, disapproved of the Scottish court’s attitude towards her husband’s liaisons and James was nonplussed.

As for the couple’s actual relationship, we don’t know for certain what to make of it. There were no signs of public discord, but by the same token, we also know that Margaret was proud and James continued an affair with a woman named Janet Kennedy until around 1510. By the same token, it’s entirely possible that the marriage was not immediately consummated out of consideration for the Queen’s age. She didn’t give birth to her first child for another three years, strong evidence that the two waited.

Interestingly, given that Henry VII and Elizabeth of York had successfully produced four children who survived childhood, the three who lived until adulthood had spotty luck with fertility. While Margaret and her younger sister, Mary, didn’t have quite as bad a go at it as their brother (and his wives), it was consistently a struggle to produce healthy sons who lived.

Throughout her marriage, Margaret gave birth to six children, only one of whom survived. Her firstborn was a son, christened James for his father, who was born at Holyrood Palace on February 21, 1507. He lived for around one year and was quickly followed to the grave by an unnamed daughter who died shortly after her birth in July 1508. A third child, Arthur, was born in October 1509, but he died at just nine months.

In that time, Margaret’s father, Henry VII, died and was succeeded by her 17-year-old brother, Henry VIII. He quickly married his brother’s widow, Katherine of Aragon, with whom Margaret would have been well-acquainted. The problem with this new reign, however, was that Henry VIII was by far less interested in the moderation and peacefulness that had defined his father’s. He was also eager to insert himself in European politics, even if that was to the detriment of England’s alliance with Scotland.

Of particular issue was the historical relationship between Scotland and France. While there had been moments of tension in the six years between Margaret’s wedding and Henry VII’s death, the most serious was over the question of Scotland renewing its its peace treaty with France, the alliance held firm. In 1511, the Vatican formed the anti-French Holy League to keep France out of Italy, and Henry VIII, following the lead of his father-in-law, Ferdinand of Aragon, joined. The end result was both disastrous and humiliating: Spain left England hanging after a declaration of war against France in April 1512.

Henry responded by urging Maximilian, the Holy Roman Emperor, to join the League and by the spring of 1513 he was ready to renew war. On June 30th, the English won the Battle of the Spurs, not quite the military coup of Agincourt, but a victory against the French all the same.

The problem with the war for James was that Scotland was bound by treaty to them both. When Henry formally invaded France in 1513, James responded by declaring war on England. King Louis XII of France’s wife, Anne of Brittany, even went so far as to appeal to James to help her and her husband, promising him a small fortune if we would act as their protector. In the end, James agreed, sending Scottish ships to join the French navy.

Meanwhile, with Henry in France, he attempted to take advantage of his absence by invading southward through Northumbria. Unfortunately for James, Katherine of Aragon was acting as her husband’s regent and she wasn’t exactly a shrinking violent. In late August she ordered all the property of Scotsmen living in England seized and raised an army led by Thomas Howard, Earl of Surrey – the same man who had escorted Margaret to Scotland a decade earlier.

After some success moving inland, the two armies met at Branxton in Northumberland. The battle would eventually become known as the Battle of Flodden, and it was described by a contemporary chronicler with, “The battle was cruel, none spared other, and the King himself fought valiantly.” Unfortunately, it also killed James, who was fatally wounded with an arrow.

As has gone down in legend, when Queen Katherine was informed of England’s victory and James’s death, she attempted to send her husband the slain King’s severed head. Dissuaded that such barbarity wasn’t English custom, she reconciled herself with sending him the bloodied jacket he had worn in battle.

Margaret had adamantly opposed the war, not least of which was because it was against her home country. She also reportedly suffered from premonitions in the months leading up to it that the conflict would kill her husband. The situation wasn’t helped by the fact she was pregnant with the couple’s last child at the time.

Following tragic ends with her first three children, Margaret had successfully given birth to a son, also named James, in April 1512. He was followed by an unnamed daughter who died shortly after birth just seven months later (perhaps begging for the question to be asked: to what extent should the young woman have been given more time in-between pregnancies?).

Thus, when James IV fell at Flodden, Margaret seamlessly transitioned from wife of the king to mother of the king. The King, however, was an infant. Margaret responded to news of her husband’s death by quickly moving her son to Stirling Castle, an impregnable fortress, and having him crowned there as James V. The coronation has become known as the “Mourning Coronation,” for reportedly the Scottish lords wept throughout it, desolate over the loss of a popular monarch and afraid for the reality of a child king.

Margaret was sworn in as regent for her son’s minority, a precarious position that wouldn’t last long. On April 30th at Stirling Castle, Margaret gave birth to another son, christened Alexander, and styled the Duke of Ross. Like her other children, Alexander would die as an infant, but rather miraculously, the one child who survived was the one with a crown on his head – James V lived until 1542, the same year his daughter, Mary Stuart, was born.

Margaret’s regency lasted barely a year. In the summer of 1514, in an attempt to give herself some protection, she secretly married Archibald Douglas, Earl of Angus, a Scottish nobleman. The union broke the terms of her late husband’s will; she was stripped of the regency and separated from her children. And rather incredibly, the situation forced Margaret to turn to the very brother who had made her a widow in the first place, putting her and her young family once more in England’s debt.

But that we’ll save for another time. The marriage of James IV and Margaret Tudor not only dictated British history for the 16th century, but put in place the succession that would eventually lead to King James VI of Scotland succeeding Queen Elizabeth I of England in 1603 and establishing the royal House of Stuart.