Cosimo was born in Florence on 12 June 1519, the son of the famous condottiere Ludovico de' Medici (known as Giovanni delle Bande Nere) and his wife Maria Salviati,[1] herself a granddaughter of Lorenzo the Magnificent.

"[3] Cosimo proved strong-willed, astute and ambitious and soon rejected the clause he had signed that entrusted much of the power of the Florentine duchy to a Council of Forty-Eight.

When the Florentine exiles heard of the death of Alessandro, they marshalled their forces with support from France and from disgruntled neighbors of Florence.

In 1537, Cosimo sent Bernardo Antonio de' Medici to Holy Roman Emperor Charles V to gain recognition for his position as head of the Florentine state.

The help granted to Charles V allowed him to free Tuscany from the Imperial garrisons and to increase as much as possible its independence from the overwhelming Spanish influence in Italy.

[dubious – discuss] Cosimo also was an active builder of military structures,[7] as a part of his attempt to save the Florentine state from the frequent passage of foreign armies.

Examples include the new fortresses of Siena, Arezzo, Sansepolcro, the new walls of Pisa and Fivizzano and the strongholds of Portoferraio on the island of Elba and Terra del Sole.

Despite his economic difficulties, Cosimo I was a lavish patron of the arts and also developed the Florentine navy, which eventually took part in the Battle of Lepanto, and which he entrusted to his new creation, the Knights of St.

Originally intended as a means of consolidating his administrative control of the various committees, agencies, and guilds established in Florence's Republican past, it now houses one of the world's most important collections of art, much of it commissioned and/or owned by various members of the Medici family.

As his more prominent ancestors had been, he was also an important patron of the arts, supporting, among others, Giorgio Vasari, Benvenuto Cellini, Pontormo, Bronzino, the architect Baldassarre Lanci, and the historians Scipione Ammirato and Benedetto Varchi.

A large bronze equestrian statue of Cosimo I by Giambologna, erected in 1598,[10] still stands today in the Piazza della Signoria, the main square of Florence.