On May 22, 1455, Richard, Duke of York engaged the forces of King Henry VI of England at the First Battle of St. Albans. The clash is now considered the traditional start date of the Wars of the Roses, a 30-year period of sporadic warfare and constant political intrigue between the rival Houses of York and Lancaster, both of whom laid claim to the English throne. Their intermittent struggle resulted in the capture, disappearance or death of scores of English nobles and would-be kings, and eventually gave rise to a new royal dynasty that ruled for more than a century. Explore nine key facts about the bloody feud that permanently altered the course of British history.

1. The Yorks and Lancasters were descended from the same family.
The Houses of York and Lancaster both traced their lineage to the sons of Edward III of the House of Plantagenet, who ruled as England’s king from 1327 until 1377. The Yorks were descended from the female relatives of Edward’s second and fourth sons, while the Lancasters were related to Edward’s third son, John of Gaunt. This complicated family tree ensured that both factions had a legitimate case for their royal lineage, though by modern standards the Yorkists’ claim was undoubtedly stronger. Nevertheless, when the Wars of the Roses first kicked off, the Lancasters had been entrenched on the throne since 1399, when Henry IV usurped power from his cousin Richard II.

King Henry VI, who was dogged by mental illness for much of his life. (Credit: National Portrait Gallery)

2. Fallout from the Hundred Years’ War helped spark the unrest.
The Wars of the Roses might never have happened if not for the tenuous state of English politics in the 1450s. The realm was still reeling from its recent defeat in the last phase of the Hundred Years’ War with France, which had drained royal coffers, fractured the nobility and sent legions of unemployed soldiers flooding into the countryside. The sorry state of affairs was compounded by the weak and witless reign of the Lancasterian King Henry VI, who suffered from a mental illness that often rendered him nearly catatonic. Richard, Duke of York was made protector of the realm during one of Henry VI’s spells, and was reluctant to step down even after the King had recovered. The conniving and jockeying for power that ensued eventually led to 1455’s First Battle of St. Albans, the first armed confrontation between York and Lancaster-aligned armies.

3. Neither side used a rose as its sole symbol.
The Wars of the Roses take their name from the color of the roses—red for Lancaster and white for York—that each house supposedly used as their emblem. This legend took root after William Shakespeare and others wrote about it, but most modern historians maintain that neither side was identified solely by a floral symbol. The white rose was just one of many badges used by the Yorks, and the red rose of Lancaster was likely not adopted until the 1480s, when the conflict was nearly over. The name “Wars of the Roses,” meanwhile, wasn’t coined until the 19th century. The struggle was better known to contemporaries as the “Cousins’ Wars.”

Margaret of Anjou

4. Queen Margaret of Anjou was the Lancasters’ most skilled strategist.
Although the Lancasters were nominally aligned behind King Henry VI, his ill health ensured that he was never a major player in the Wars of the Roses. The de facto leader of the Lancaster faction was instead his beautiful and cunning queen, Margaret of Anjou. Margaret masterminded many of the Lancasters’ alliances, and was responsible for raising an army that killed Richard of York and freed Henry VI from capture. She was later forced into exile in France after the Lancasters were ousted from power, but continued plotting and eventually helped orchestrate a 1470 invasion of England that briefly restored her husband to the throne. As brutal as she was brilliant, Queen Margaret showed little mercy to her rivals, most of whom she considered traitors. In one famous episode, she even allowed her 7-year-old son to choose the method of execution for two captured Yorkists, and complied when the boy decreed that they should “have their heads taken off.”

5. Both sides gained and lost power multiple times.
The Wars of the Roses saw the Yorks and Lancasters play musical chairs with the English throne. Richard, Duke of York nearly unseated the Lancastrian King Henry VI in 1460, only to be killed in battle a few months later. York’s son Edward IV, meanwhile, crushed the Lancasters in battle and claimed the throne before being briefly deposed in 1470. He quickly won back his kingship and ruled for several years of relative peace, but his sudden death in 1483 launched yet another period of infighting that saw his heirs murdered and the Yorkist Richard III and the Lancastrian Henry Tudor both elbow their way into power. In total, the Wars resulted in five different rulers in the span of only 25 years, three of whom were killed or executed by their rivals.

Edward IV

6. The Wars included one of the bloodiest battles ever fought on English soil.
Despite dragging on more than 30 years, the Wars of the Roses only amounted to a few months of actual fighting and less than 20 significant battles. The most gruesome of these came in March 1461, when the Yorkist forces of Edward IV met Margaret of Anjou’s Lancastrians near the village of Towton. The ensuing battle, fought amidst a blinding snowstorm, may have involved as many as 80,000 men. The two sides began by exchanging punishing volleys of arrows before clashing in fierce hand-to-hand combat. The fighting went on for 10 exhausting hours—contemporary chroniclers claimed a nearby river ran red with blood—but the Yorkists eventually routed the Lancastrians, allowing Edward IV to tighten his grip on the throne. While estimates of casualties at the Battle of Towton vary, it may have claimed as many as 40,000 lives—more than in any battle ever fought in Britain.

7. Many key figures switched allegiances over the course of the conflict.
Double-crossing was rampant during the Wars of the Roses, and many key battles turned on acts of treachery. The most extraordinary defection came in 1470, courtesy of the Earl of Warwick, a popular nobleman and power broker nicknamed the “Kingmaker.” Warwick was originally a staunch supporter of Richard, Duke of York, and had helped propel the Duke’s son Edward IV to the throne. But after the King and the “Kingmaker” had a falling out, Warwick joined Edward’s brother, the Duke of Clarence, in leading a rebellion against him. The coup failed, so Warwick and Clarence fled to France, where they partnered with their former archenemy, the exiled Lancastrian Queen Margaret of Anjou. These unlikely allies managed to briefly unseat King Edward during an invasion of England, but their triumph turned to defeat after Clarence defected back to the Yorkists and Warwick died in battle. Margaret of Anjou was later captured and Henry VI and his son were killed, leaving the House of Lancaster in ruins.

Edward and Richard, the "Princes in the Tower."

8. The Wars led to one of the most perplexing disappearances in British history.
After the Yorkist King Edward IV died in 1483, the crown passed to his eldest son, Edward V. Since Edward was only 12 years old, his uncle Richard, Duke of Gloucester was made protector of the realm until he came of age. Edward and his younger brother Richard of Shrewsbury were sent to live in the Tower of London, but they turned from honored guests into prisoners after their uncle and his allies invalidated their deceased father’s marriage and declared them illegitimate. The Duke usurped the throne and was crowned King Richard III shortly thereafter, and the two “Princes in the Tower” vanished without a trace. The skeletons of a pair of children were later found underneath one of the Tower’s staircases in 1674, leading many historians to conclude that Richard III had the boys killed. The remains have never been authenticated, however, and the Princes’ true fate remains a mystery.

The death or Richard III at the Battle of Bosworth Field. (Credit: Hulton Archive/Getty Images)

9. The Wars reached their climax at 1485’s Battle of Bosworth Field.
Richard III’s power grab alienated his Yorkist allies, some of whom eventually flocked to the banner of Henry Tudor, an exiled nobleman and distant relative of the Lancasters who had made a claim to throne. Tudor landed in England in 1485 and rallied his supporters, and on August 22, he confronted Richard III at the Battle of Bosworth Field. The clash ended in a decisive Tudor victory, and Richard III was killed during the fighting by a vicious blow to the head. Tudor was immediately crowned King Henry VII, launching a new Tudor Dynasty that flourished until the early 17th century. He went on to unite the Yorks and Lancasters once and for all by marrying Elizabeth of York, Edward the IV’s daughter. To symbolize the end of the Wars of the Roses, he also adopted a new “Tudor rose” emblem that incorporated both the white rose of the Yorks and the red of the Lancasters.