Today in 1471 the Battle of Barnet was fought in England between the House of York’s Edward IV and the House of Lancaster’s Richard Neville, Earl of Warwick. The battle resulted in Lancaster’s defeat and Warwick, the “Kingmaker,” was killed while attempting to escape the field. At the time of the battle, Edward IV had recently been deposed thanks to Warwick’s betrayal when he defected to the Lancastrian cause, turning his back on the House and family on which he had built his career.

The year before, he, alongside Edward’s younger brother, George, Duke of Clarence had rebelled against Edward and sailed to France where they met with King Louis XI and made peace with their former adversary, Marguerite of Anjou. Her husband, Henry VI, was residing in the Tower of London at the time, a prisoner of Edward’s government since 1465. Thus, it was the Queen who served as the rallying point for Lancaster, with her adolescent son, Prince Edward, waiting in the wings.

Warwick and Marguerite made a shaky peace and cemented it in the marriage of their children. In December 1470 the bizarre union of Prince Edward and Lady Anne Neville was solemnized, a legal way of ensuring Warwick remained true to the cause.

After the marriage Warwick was sent to England to topple Edward IV’s government, which he swiftly did. Henry VI was reinstated and for a few months England was Lancastrian once more, however tenuous the hold. The great lords of Lancaster didn’t trust Warwick; indeed, they loathed him. And Marguerite wasn’t quick to join him, which only further underlined the shakiness of the strange bedfellows’ alliance.

Finally, in March 1471, she did. She landed in England with her son and daughter-in-law on the same day as the Battle of Barnet and news of Warwick’s defeat and death was shared with her shortly after she arrived. It could have been solved quickly enough – all she had to do was re-board a ship and return to the exiles’ court she had created for herself and her followers. It was a shadow of the life she had once led, but at least it was one of safety.

Reportedly that’s exactly what she wanted to do. Her desire, and her earlier hesitancy to return to England, were more than likely premised on the need to protect her son. Her only child, he was her last link to her adopted country and her husband’s only direct heir. Without him the true Lancastrian line ended.

Even so, it wasn’t what her advisers wanted. By many accounts, she was convinced to stay and finish what Warwick had started by her son and her closest councilor, Edmund Beaufort, Duke of Somerset (son of the earlier Somerset who the Yorkists claim was the true father of Prince Edward). Edward’s wish to stay is easy enough to parse, if one makes assumptions about his personality – he was 17; England was his birthright; he wanted to avenge what had been done to his father. But what of the seasoned politicians by their side?

It was a pure fight or flight decision, but the decision to “fight” makes a certain amount of sense. Henry VI had been deposed in 1461, making it 10 long years since their party had been in power. Edward IV was a seasoned soldier, a relatively capable monarch and he had the benefit of younger brothers and a plethora of other male relatives to back him. Even more, his wife, Elizabeth Woodville, had finally given birth to a son and heir just a few months before. Two decades younger than Henry, physically strong and popular, Edward seemed like the better king.

That Lancaster had made it as far as they had – that their king was back on the throne and this moment of uncertainty had presented itself likely felt like their last, best shot. They chose to roll the dice.

Two months later the Battle of Tewkesbury was fought and both Prince Edward and Somerset were killed. The night after Edward IV returned to London he ordered the quiet execution of Henry VI. Marguerite was brought to the Tower of London as a prisoner, before being moved to house arrest outside of the capitol until her cousin, Louis XI, paid her ransom a few years later. She died, penniless and alone, in 1482 at the age of 52.

In a turn of events that would have surprised most in 1471, Lancaster wasn’t over. Henry VI’s half-nephew, Henry Tudor, was spirited out of England by his uncle, Jasper Tudor, that spring. They landed in Brittany where they lived in tense, political exile for 14 years until they had the opportunity to depose Edward IV’s younger brother, Richard III, in 1485. He, in turn, married Edward’s daughter, Elizabeth of York, and founded the House of Tudor. A new House, yes, but one that positioned itself as merging the two great royal families of England. It would rule uninterrupted until 1603.

But what would have happened if Marguerite had left when she supposedly wanted to? It’s hard to say. Their defeat at Tewkesbury effectively quashed a rallying point for many of her followers and it was followed by a relative period of peace in the midst of the civil war. Had her husband and son still been alive it’s possible another opportunity would have presented itself, though difficult to imagine when, how or what the odds of victory would have been. Certainly, too, the older Prince Edward became the less likely he would have been satisfied watching another man govern his country.

There was an air of inevitability to the decision to stay and fight, a sense of “let’s get this over with, once and for all.” In a way, it’s the defeat the Yorkists wanted in 1461, but Marguerite had eluded them and Edward IV had shown Henry VI mercy by letting him live once he got hold of him.

But however much 1471 marked the end of Marguerite’s public life, it was a personal defeat for her nemesis. Edward IV lost a friend, cousin and mentor in Warwick. The remaining 12 years of his reign would be decidedly different from the first 10. He became harder, more cynical and his rule became one of protection – of himself, of his son and of his line. This is most markedly seen in 1475 when he dropped a military campaign against France and accept an annuity which enriched his coffers and nearly made his daughter queen of France. It was a Henry VII-esque move and utterly at odds with the bravado and earnestness of his earlier career.

Whatever the lesson coming out Barnet and Tewkesbury were, he learned them well.