A regent is “a person appointed to administer a state because the monarch is a minor, is absent or is incapacitated.”

Catherine de’ Medici was born on 13 April 1519 as the daughter of Lorenzo II de’ Medici and Madeleine de La Tour d’Auvergne. She was orphaned just a month later when her mother died of either puerperal fever or plague, and her father died from syphilis. Catherine was raised by her aunt, Clarice Strozzi. Her family was briefly overthrown in Florence in 1527, and Catherine was taken hostage and placed in a convent. By 1530 the siege was over.

Her uncle, Pope Clement VII, set about finding a husband for her. He had plenty to choose from, and when Francis I of France proposed his second son, Henry, Duke of Orléans in 1533, he jumped at the chance. Their marriage took place in the Église Saint-Ferréol les Augustins in Marseille on 28 October 1533. King Francis reportedly stayed in the bedroom during the consummation to ensure it was done. They were visited by Pope Clement VII in the morning, who added his blessings. Her uncle died in 1534, and the next Pope refused to pay the enormous dowry promised, leaving Catherine embarrassed. Meanwhile, her husband hardly noticed her and openly took mistresses. It was no surprise then that Catherine conceived no child in the first ten years of their marriage.

The pressure to have children became even greater when Henry’s older brother Francis died suddenly in 1536, leaving Henry as heir to the throne. She gave birth to her first son on 19 January 1544. She spent the next 22 years bearing ten children, though not all would live to adulthood.

Catherine and Henry became King and Queen of France when King Francis I died on 31 March 1547, but during her husband’s lifetime, she was hardly the first lady of the court. This place was reserved for Diane de Poitiers, her husband’s mistress. Mary, Queen of Scots, was raised alongside Catherine and Henry’s children as she was promised to their eldest son, Francis.

The marriage of their daughter Elisabeth to Philip II of Spain on 22 June 1559 was celebrated in grand style and was followed by five days of jousting. Henry took part in the jousting, but he was injured when a lance shattered into his face. Several splinters stuck out of his eye and head. He was carried back to the Château de Tournelles, where five splinters were removed. Over the next ten days, the King’s health went up and down. He slowly lost his sight and speech and finally died on 10 July 1559.

Her son was now King Francis II, with his wife Mary, Queen of Scots by his side. Francis was deemed old enough to rule for himself, but Francis relied on her nonetheless. Diane de Poitiers was unceremoniously turned away. In 1560 it became clear that Francis was dying of an ear abscess. Catherine made a pact with Antoine de Bourbon, King of Navarre by right of his wife Joan III. Antoine was a First Prince of the Blood and in the line of succession after Catherine’s sons as a male-line descendant of Louis IX of France. He would renounce his right to the regency of Catherine’s second son Charles in return for the release of his brother, Louis, Prince of Condé. When Francis died on 5 December 1560 Catherine was appointed as governor of France. Catherine wrote to her daughter Elisabeth: “My principal aim is to have the honour of God before my eyes in all things and to preserve my authority, not for myself, but for the conservation of this kingdom and for the good of all your brothers”.

Charles IX was just nine years old, and Catherine kept him close to her at all times. She even slept in the same chamber. The challenges ahead were difficult. She attempted to build bridges with the Protestants, but the Massacre of Vassy sparked the French Wars of Religion. The recently released Prince of Condé had raised an army and formed an alliance with France. Catherine fought back with the royal army, and she visited the deathbed of Antoine de Bourbon, who was fatally injured when Catherine’s army laid siege to Rouen.

Her son was declared to be of age on 17 August 1563, but he showed little interest in government. By 1567 Huguenot forces tried to ambush the King, which renewed the war. From then on, Catherine did not wish to compromise any further. However, by 1570 the royal army was quickly running out of money, and the Peace of Saint-Germain-en-Laye perhaps showed much more toleration than Catherine wanted.

Meanwhile, Catherine was looking to make dynastic marriages for her children. Charles IX married Elisabeth of Austria, daughter of Maximilian II, Holy Roman Emperor in 1570. After her daughter Elisabeth died in childbirth, she offered her youngest daughter Margaret to Philip II of Spain. She later married the Huguenot Henry III of Navarre, the son of Antoine de Bourbon and Joan III. However, when Joan arrived in Paris to buy clothes for the wedding, she was suddenly taken ill, and she died. Catherine was accused of murdering with poisoned gloves.

Nevertheless, the wedding went ahead on 18 August 1572. The following St. Bartholomew’s Day Massacre left a stain on Catherine’s reputation. The court expected a Huguenot uprising in revenge for the attack on an admiral a few days earlier. Charles IX ordered to strike first, now that the Huguenot leaders were still in Paris for the wedding. The massacre in Paris lasted almost a week and spread to many more parts of France, where it lasted the rest of the summer. Henry III of Navarre had converted to Catholicism to avoid being killed.

In 1574 Charles XI died at the age of 23, leaving behind a young daughter. He named Catherine as regent as his brother the Duke of Anjou was in the Polish-Lithuanian Commonwealth, where he had been elected King the year before. He returned to France quickly and married Louise of Lorraine in February 1575, but their marriage would remain childless. The death of her youngest son Hercule Francis (he later went by just Francis in honour of his older brother) in 1584 shattered Catherine’s dream. Henry III of Navarre was now the heir presumptive to the throne.

Catherine wrote to Pomponne de Bellièvre, a statesman: “I am so wretched to live long enough to see so many people die before me, although I realise that God’s will must be obeyed, that He owns everything, and that he lends us only for as long as He likes the children whom He gives us.”

Her youngest daughter Margaret was at least conveniently married to Henry III of Navarre, but their marriage proved childless, and Margaret took lovers. Margaret fled from Navarre in 1585 and begged her mother for money. She was later locked up in Château d’Usson and never saw her mother again. Catherine now acted as a diplomat and headed off on an eighteen-month journey to the south of France to meet with the Huguenots. When she returned to Paris, the Venetian Ambassador wrote: “She is an indefatigable princess, born to tame and govern a people as unruly as the French: they now recognise her merits, her concern for unity and are sorry not to have appreciated her sooner.”

Nevertheless, the tensions between Catholics and Protestants spiralled out of control. In 1588, the court assembled at Blois for a meeting of the Estates, while Catherine was in bed with a lung infection. On 23 December 1588 the Duke of Guise, the leader of the Catholic League, was called to Blois where he was assassinated in the King’s bed-chamber. Eight other members of the Guise family were rounded up and killed. When Catherine was informed, she reportedly said: “Oh, wretched man! What has he done? … Pray for him … I see him rushing towards his ruin.”

Catherine died on 5 January 1589 and was provisionally buried at Blois. Her son was stabbed to death just 18 months later. Henry III of Navarre was now also Henry IV of France and Catherine’s dynastic nightmare had come true.