Italian adventurer who dominated the French government during the first seven years of the reign of King Louis XIII (reigned 1610–43).

The son of a Florentine notary, Concini joined the entourage of Marie de Médicis shortly before she left Italy to marry the French king Henry IV (reigned 1589–1610). In 1601 he married the queen's foster sister, Leonora Dori Galigai. Concini exercised such a strong influence over the queen that Henry IV threatened several times to banish him from the court. Upon the assassination of the king, Concini (now Marquis d'Ancre) and his wife acted as chief advisers to Marie, who had become regent for her young son, King Louis XIII. The Concinis treated Louis with contempt and set about enriching themselves at France's expense.

In 1613 Concini was appointed marshal of France, even though he had never seen combat. Taking advantage of his unpopularity, the great nobles, led by Henri II de Bourbon, prince de Condé, raised two rebellions. In 1616 Concini managed to have Condé arrested. He momentarily strengthened his position by bringing such able administrators as the future Cardinal de Richelieu into the government; but by 1617 the nobles were again threatening to revolt. Louis XIII's favourite, Charles d'Albert de Luynes, then initiated a plot against the marquis. Concini was shot by the royal guards on the drawbridge of the Louvre, and a mob dismembered his corpse. His widow was condemned to death for sorcery and was beheaded and burned on July 8, 1617.