Girl junior by François I, grand duke of Tuscany, relationship of Catherine de Médicis, it marries Henri IV in 1600 in Lyon, marriage made possible by the cancellation of that of Henri IV and Marguerite de Valois. She gives six children to the king, and does not play any political role until the assassination of Henri IV, in 1610.

Hardly two hours after the assassination of the king (May 14th, 1610), the Parliament recognizes it regent of its son Louis XIII, then 9 years old. If the queen gives initially the impression to hesitate between the policy pursued by the old servants of Henri IV (“greybeards”), and that of the devout party (very catholic and pro-Spanish), it finally seems to choose this last while forcing with the resignation Sully, Minister for Finance, Protestant confession.

Very quickly, it appears with the opinion that France is controlled by the successive favorites of Marie, of which the Concini minister and his wife Leonora Galigaï, to which it grants many loads and wide powers. Its pro-Spanish attitude is not long in worrying the Huguenot ones, while large kingdom do not cease being agitated in spite of the generous pensions which are versed for them. Soon, the cases of the State are empty, and Marie de Médicis decides to convene the general states in 1614 to solve this problem. This decision is interpreted like a sign of weakness of monarchy, but Marie can skilfully benefit from divisions between the three orders to reinforce her power. She thus dissolves the general states, four months after their convocation, under pretext of inefficiency.

In spite of the majority of Louis XIII, proclaimed in 1614, the queen continuous mother to take an active part in the political intrigues. She scrambles herself with her son who, after having made assassinate Concini, makes it lock up in 1617 with the castle of Blois, from where she escapes in 1619 to take the head of a revolt of large of the kingdom against the king.

The coalition of large is overcome by the royal army with the battle of Bridge-of-It (1620), but Richelieu succeeds in reconciling the queen with Louis XIII, diplomatic prowess which to him is worth the cardinal's hat and the entry with the Council of the king. Richelieu releases himself however quickly from the influence of the queen, who tries then by all the means of ousting it power.

The competition between the cardinal and its old protective finds its apogee during the “Day of Dupes”, on on November 10th, 1630, where Richelieu assoit definitively his power. Marie de Médicis, exiled initially in Compiegne, flees in Brussels (1631), then in England (1638) and Germany (1641). Louis XIII will never authorize it to return to France.

Disputed on the political plan, Marie de Médicis - friendly queen florentine of arts - however contributed to maintain the print Italian on the court of France, and ensured successfully the promotion of the Baroque art in the kingdom, by calling upon the Rubens painter in particular for the decoration of her palate of Luxembourg.