Wars of Religion: 1562 - 1576
The 'Wars of Religion' took place in France over the course of four decades, from 1562-1598. Rather like the Hundred Years War, they consisted of a series of wars rather than one continuous conflict. But this time it was a long series of civil wars, between Catholics and Protestants (known as Huguenots - hence the wars are also referred to as the Huguenot Wars) , that led to so much bloodshed.
At the time the wars started, the Huguenots constituted just 7% of the population of France. But by a geographical accident, they found themselves strategically placed for a battle that was really as much of a political battle as a religious battle. The big struggle was between the King and the great noble families, and the protestant struggle to be able to worship freely got tied up with this political struggle.
Henry of Navarre, later to become Henry IV, was a Protestant leader, after Lois I de Condé and Gaspard de Coligny; the Catholics were led by the Guise family, with the support of the 'Politiques'. Catherine de Medici and her sons played an important role as they moved between the two sides.
Francis II became King of France in 1559, when he was just 15 years old. Trying to take advantage of his weak position, the Guises and two other families battled to control the throne, and the Guises won through - they were also fanatical Catholics.
When Francis II died just a year later, his even younger brother (Charles IX) took the throne, but because of his young age it was his mother, Catherine de Medici, who controlled the kingdom. Catherine de Medici, seeing the threat posed by the Guise family, gave support to the two other leading noble families, the Bourbons and the Montmorency-Chatillons. But supporting these two families meant she had to support the Huguenots, and in 1562 the right was granted to Huguenots to worship outside towns, and to hold church assemblies. But Catherine de Medici herself remained a Catholic.
In March 1562, all this religious freedom had become too much for the Guise family, and the Duke of Guise led an army against a protestant church in Champagne. The entire congregation, unarmed men, women and children were slaughtered (see picture: the Massacre of Wassy)
This was to be the start of almost 40 years of war. During the first three civil wars (1562–63, 1567–68, 1568–70) Catherine de Medici struggled to find a balance between the Catholic and Protestant sides, with some success, and a temporary peace was found in 1570.
But this was not too last. Catherine plotted with the Guise family to assassinate a member of the Montmorency-Chatillons family, but the plot failed and the truth of the attempt soon emerged. A Protestant uprising seemed likely, and to pre-empt this Catherine persuaded Charles IX to act first. The most infamous period of the wars was about to start.
Wars of Religion & the Saint Bartholomew Massacre : 1572 - 1588
The St Bartholomew Massacre : On the 24th August 1572, forces acting for the King executed several thousand Huguenots in Paris. These included Coligny, the nobleman that Catherine de Medici had tried to have assassinated. In the days that followed a further 20,000 Huguenots were tracked down and executed.

Rarely to this day has such a sytematic 'witchhunt' been as rapid and brutal as those few days in 1572.
It was also a turning point for the Huguenots, until that point generally as peace-loving as was possible in those turbulent times. From the time of the St Bartholomew Massacre things changed, with the Huguenots newly enthused to battle against a church that they now saw as being dominated by the devil.
This launched the fourth and fifth civil wars, until in 1576 the Huguenots were granted freedom to worship anywhere in France except Paris.
As we often learn, history repeats itself, and the Catholics formed a Holy League, and succeeded in convincing Henry III - Henry III, the younger brother of Francis II and Charles IX had taken the throne in 1576 - that he should repeal the earlier freedoms.
Inevitably this led to a further Huguenot uprising, a further peace agreement (that Henry III failed to carry out), and further civil wars.
But the wars were now being fought between two almost fanatical opposed groups, and it was not at all clear how a solution could emerge. Henry III, like Catherine de Medici before him, tried to find compromise positions among and between the less radical groups.
In 1584 Henry III acknowledged that Henry of Navarre, a protestant, would be his heir. This prompted Henri de Guise to renew the Holy League, and a new civil war began (1585 - 1589). This time with the help of Philip II of Spain, the Catholic extremists took control of France, drove the King out of Paris, and again set forth on a series of terrible massacres of ordinary citizens.
Wars of Religion & the Edict of Nantes: 1588 - 1598
Henri de Guise was assassinated in 1588 and Henry III in 1589.
At that time Henry III had been planning to attack Paris with his Huguenot cousin, Henry de Navarre. With the murder, Henry of Navarre was legally entitled to the throne, and continued to fight against the Holy League.
Despite the Holy League again having help from Spain, Henry had some significant victories. After converting to Catholicism in 1593 he entered Paris in 1594. Henry IV was notable in that he considered the future of France to be more important than the ongoing religious battles, and converted to Catholicism on that basis - that was the only way to bring peace to France. In 1598 he took the throne as King Henry IV (pictured).
In 1598, the Edict of Nantes granted freedom of worship to the whole of France. In the same year the Treaty of Vervins was signed between France and Spain. These two steps essentially ended the Wars of religion in France, and one of the most terrible chapters in it's history was brought to an end.
In the century to come much of the hard won ground would be refought, but for the time being France at last had a period of peace, after almost four decades of civil wars and two of the most brutal and senseless systematic exterminations that Europe had seen, or would see again until the 20th century.