At first Catherine kept the nine-year-old king, who cried at his coronation, close to her, and slept in his chamber.
She presided over his council, decided policy, and controlled state business and patronage.
However, she was never in a position to control the country as a whole, which was on the brink of civil war.
In many parts of France the rule of nobles held sway rather than that of the crown.
The challenges Catherine faced were complex and in some ways difficult for her to comprehend as a foreigner.

She summoned church leaders from both sides to attempt to solve their doctrinal differences.
Despite her optimism, the resulting Colloquy of Poissy ended in failure on 13 October 1561, dissolving itself without her permission.
Catherine failed because she saw the religious divide only in political terms.
In the words of historian R. J. Knecht, "she underestimated the strength of religious conviction, imagining that all would be well if only she could get the party leaders to agree".
In January 1562, Catherine issued the tolerant Edict of Saint-Germain in a further attempt to build bridges with the Protestants.
On 1 March 1562, however, in an incident known as the Massacre of Vassy, the Duke of Guise and his men attacked worshipping Huguenots in a barn at Vassy (Wassy), killing 74 and wounding 104.
Guise, who called the massacre "a regrettable accident", was cheered as a hero in the streets of Paris while the Huguenots called for revenge.
The massacre lit the fuse that sparked the French Wars of Religion.
For the next thirty years, France found itself in a state of either civil war or armed truce.

Within a month Louis de Bourbon, Prince of Condé, and Admiral Gaspard de Coligny had raised an army of 1,800.
They formed an alliance with England and seized town after town in France.
Catherine met Coligny, but he refused to back down.
She therefore told him: "Since you rely on your forces, we will show you ours".
The royal army struck back quickly and laid siege to Huguenot-held Rouen.
Catherine visited the deathbed of Antoine de Bourbon, King of Navarre, after he was fatally wounded by an arquebus shot.
Catherine insisted on visiting the field herself and when warned of the dangers laughed, "My courage is as great as yours".
The Catholics took Rouen, but their triumph was short lived.
On 18 February 1563, a spy called Poltrot de Méré fired an arquebus into the back of the Duke of Guise, at the siege of Orléans.
The murder triggered an aristocratic blood feud that complicated the French civil wars for years to come.
Catherine, however, was delighted with the death of her ally. "
If Monsieur de Guise had perished sooner", she told the Venetian ambassador, "peace would have been achieved more quickly".
On 19 March 1563, the Edict of Amboise, also known as the Edict of Pacification, ended the war.
Catherine now rallied both Huguenot and Catholic forces to retake Le Havre from the English.
At first Catherine kept the nine-year-old king, who cried at his coronation, close to her, and slept in his chamber. She presided over his council, decided policy, and controlled state business and patronage. However, she was never in a position to control the country as a whole, which was on the brink of civil war. In many parts of France the rule of nobles held sway rather than that of the crown. The challenges Catherine faced were complex and in some ways difficult for her to comprehend as a foreigner.
She summoned church leaders from both sides to attempt to solve their doctrinal differences. Despite her optimism, the resulting Colloquy of Poissy ended in failure on 13 October 1561, dissolving itself without her permission. Catherine failed because she saw the religious divide only in political terms. In the words of historian R. J. Knecht, "she underestimated the strength of religious conviction, imagining that all would be well if only she could get the party leaders to agree". In January 1562, Catherine issued the tolerant Edict of Saint-Germain in a further attempt to build bridges with the Protestants. On 1 March 1562, however, in an incident known as the Massacre of Vassy, the Duke of Guise and his men attacked worshipping Huguenots in a barn at Vassy (Wassy), killing 74 and wounding 104. Guise, who called the massacre "a regrettable accident", was cheered as a hero in the streets of Paris while the Huguenots called for revenge. The massacre lit the fuse that sparked the French Wars of Religion. For the next thirty years, France found itself in a state of either civil war or armed truce.
Within a month Louis de Bourbon, Prince of Condé, and Admiral Gaspard de Coligny had raised an army of 1,800. They formed an alliance with England and seized town after town in France. Catherine met Coligny, but he refused to back down. She therefore told him: "Since you rely on your forces, we will show you ours". The royal army struck back quickly and laid siege to Huguenot-held Rouen. Catherine visited the deathbed of Antoine de Bourbon, King of Navarre, after he was fatally wounded by an arquebus shot. Catherine insisted on visiting the field herself and when warned of the dangers laughed, "My courage is as great as yours". The Catholics took Rouen, but their triumph was short lived. On 18 February 1563, a spy called Poltrot de Méré fired an arquebus into the back of the Duke of Guise, at the siege of Orléans. The murder triggered an aristocratic blood feud that complicated the French civil wars for years to come. Catherine, however, was delighted with the death of her ally. "If Monsieur de Guise had perished sooner", she told the Venetian ambassador, "peace would have been achieved more quickly". On 19 March 1563, the Edict of Amboise, also known as the Edict of Pacification, ended the war. Catherine now rallied both Huguenot and Catholic forces to retake Le Havre from the English.
Catherine de' Medici