Anne Somerset’s new book Queen Anne: The Politics of Passion takes a fresh new look at the life of England’s last Stuart monarch and discovers a woman who, despite great obstacles, succeeded in uniting her realm and setting the stage for its later global dominance. Constantly underestimated and later the subject of sharp words and devastatingly effective gossip from unexpected quarters, Anne has received short shrift from historians, a fact that Queen Anne: The Politics of Passion may do much to correct.

In recognition of Somerset’s outstanding new biography, here are four other queens, in chronological order, who rose to power against great odds and ultimately changed history.

Boudica (? -61 AD)
Boudica: Iron Age Warrior Queen by Richard Hungley and Christina Unwin

When King Prasutagus of the Celti Iceni tribe died, Rome must have assumed that what was left of his kingdom would be easy pickings. Prasutagus had left a will dividing his estate between the Emperor, his wife Boudica, and their two daughters, but it wasn't enough to sate the greed of the empire. Rome invaded and enslaved the Iceni, and when Boudica protested, they publicly flogged her and raped her daughters.

Boudica, remembered as a tall, fierce woman with waist-length red hair who carried a spear and wore a warrior’s torque, was no pushover. She promptly rallied together an army of Celtic warriors and set about hacking and burning their way through Roman-occupied Britain. She and her army killed tens of thousands and burned several Roman cities to the ground, including Londinium -- later known as London. It took three Roman legions to crush Boudica’s rebellion. By that time, it probably occurred to more than a few Romans that it would have been cheaper and easier to just leave Boudica alone.

Eleanor of Aquitaine (1137-1204)
Eleanor of Aquitaine: A Life by Alison Weird

The independent-minded wife of Louis VII, King of France, Eleanor of Aquitaine pledged thousands of soldiers to the Catholic church for use in the Second Crusade. Not happy to sit on the sidelines, Eleanor and 300 of her ladies also joined the fight, tending those wounded on the battlefield. It was a major scandal in a time when proper women -- especially queens -- were expected to mind the home while their husbands went to war.

A conflict with her husband regarding military strategy resulted in her announcing that their marriage was not legitimate. Nonetheless, Louis succeeded in convincing Eleanor to return to his side -- at least for a while. A couple of years later their marriage was annulled and Eleanor married Henry II, the future king of England. Eleanor’s service in the Crusades angered the Vatican enough for them to decree that women could not serve in future crusades.

Catherine de Medici (1547-1559)
Catherine de Medici: Renaissance Queen of France by Leonie Frieda

Daughter of Lorenzo de Medici (the prince for whom Machiavelli wrote his famous book The Prince), Catherine was married off at the age of fourteen to Henry, Duke of Orleans, the heir to the throne of France. Henry took no interest in Catherine, preferring instead to openly consort with a string of mistresses. When Henry died in a jousting accident, their son Francis, one of ten children, became heir. Francis was a sickly child, and Catherine was forced to assumed a more prominent role in the court after various royal families began to plot against her.

Catherine moved to protect her children and their birthright, in the process making a number of powerful enemies. Conflicts at court escalated and soon spread to the battlefield where Catherine -- as Queen Regent for three of her children -- played a pivotal role in the battle between the Catholics and Huguenots. Rumors that she used poison to dispose of her enemies dogged her entire reign, but there is little solid evidence that this was the case.

Empress Dowager Cixi (1835-1908)
Empress Dowager Cixi: The Concubine who Launched Modern China by Jung Chang

As a teenager, Cixi was chosen to be one of the emperor’s concubines. When the emperor died in 1861, their five-year-old son Zaichun became the heir to the throne and Cixi was named Empress Dowager. Cixi promptly launched a coup against the palace regents who had been named by her husband before his death and became the de factor ruler of China.

Under her reign, the nation of China, stuck in Medieval times, was brought into the modern era. Foot-binding and other cruel practices were outlawed, and inventions like electricity and the telegraph were integrated into the nation’s aging infrastructure.