Duke and later Grand Duke of Tuscany
Villa at Castello 1519 - 1574

The son of Giovanni dalle Bande Nere and Maria Salviati, who was also grand-daughter of Lorenzo the Magnificent, Cosimo was to finally reunite the blood of both branches of the family. He was placed in power immediately after the assassination of Duke Alessandro by the magnates of the city (Filippo Strozzi, Niccolò Acciaiuoli, Baccio Valori and Francesco Guicciardini, who perhaps hoped he would marry his daughter Lisabetta), who obviously thought that they would be able to condition this nineteen year old boy, who had been brought up in the country, as they wished. They were quite wrong: Cosimo soon showed his true temperament and, with an able strategem, managed to concentrate all the power in his own hands. Led by the Strozzi family, his opponents took up arms against him but were beaten at the battle of Montemurlo on July 31st 1537.
Having ensured his throne, Cosimo re-established law and order within the State, promoting justice and protecting the weaker members of the community. He encouraged the growth of trade and industry, started to reclaim the swampy land of the Maremma, founded the Order of the Knights of St. Stephen to ward off the threat of the Barbary pirates and organized a Tuscan militia so as not to have to call in mercenary troops.

In 1539 he married the beautiful and extremely rich daughter of the Viceroy of Naples, Eleonora of Toledo, who gave him eleven children and the royal palace at Pitti (she died with her sons Giovanni and Garzia in 1562, when she was only forty; all three of them struck down by malarial fever while travelling to Pisa).
Meanwhile Giorgio Vasari designed the Uffizi and transformed Palazzo Vecchio (the seat of the government and initially also the home of the Ducal family) with decorations that celebrated the sovereign and his house, Benvenuto Cellini cast his Perseus (1545-54) and Ammannati built the new Bridge at Santa Trinita (1566), after the flood of 1557 had swept the old one away. A new fever for art and building invaded the entire city.
Thanks to the support of the Empire, Cosimo later managed to conquer Siena and, after having come close to being offered the crown by the Corsi family in 1567, he was finally given the long desired title of Grand Duke (1569) by Pope Pius V and later by the Emperor Maximilian II, which gave him kingly rights; he also managed to arrange an Imperial marriage for his eldest son Francesco, uniting him with Joan of Austria, the Emperor's sister. Thus the Medici became one of the great European dynasties.