The next ruler came from the younger branch, to which we now turn.  Old Giovanni di Bicci had two sons, Cosimo and Lorenzo.  Lorenzo’s son, Pier Francesco de’ Medici, had a son Giovanni de’ Medici.  This Giovanni, who married Caterina Sforza of Milan, had also a son named Giovanni, born in 1498, and it was he who was the rightful heir when Lorenzo, Duke of Urbino, died in 1519.  He was connected with both sides of the family, for his father, as I have said, was the great grandson of the first Medici on our list, and his wife was Maria Salviati, daughter of Lucrezia de’ Medici—­herself a daughter of Lorenzo the Magnificent—­and Jacopo Salviati, a wealthy Florentine.  When, however, Lorenzo, Duke of Urbino, died in 1519, Giovanni was a young man of twenty-one with an absorbing passion for fighting, which Clement VII (then Giulio) was only too keen to foster, since he wished him out of the way in order that his own projects for the ultimate advancement of the base-born Alessandro, and meanwhile of the catspaw, the base-born Ippolito, might be furthered.  Giovanni had already done some good service in the field, was becoming famous as the head of his company of Black Bands, and was known as Giovanni delle Bande Nere; and his marriage to his cousin Maria Salviati and the birth of his only son Cosimo in 1519 made no difference to his delight in warfare.  He was happy only when in the field of battle, and the struggle between Francis and Charles gave him ample opportunities, fighting on the side of Charles and the Pope and doing many brave and dashing things.  He died at an early age, only twenty-eight, in 1526, the idol of his men, leaving a widow and child in poverty.

Almost immediately afterwards came the third banishment of the Medici family from Florence.  Giovanni’s widow and their son Cosimo got along as best they could until the murder of Alessandro in 1537, when Cosimo was nearly eighteen.  He was a quiet, reserved youth, who had apparently taken but little interest in public affairs, and had spent his time in the country with his mother, chiefly in field sports.  But no sooner was Alessandro dead, and his slayer Lorenzino had escaped, than Cosimo approached the Florentine council and claimed to be appointed to his rightful place as head of the State, and this claim he put, or suggested, with so much humility that his wish was granted.  Instantly one of the most remarkable transitions in history occurred:  the youth grew up almost in a day and at once began to exert unsuspected reserves of power and authority.  In despair a number of the chief Florentines made an effort to depose him, and a battle was fought at Montemurlo, a few miles from Florence, between Cosimo’s troops, fortified by some French allies, and the insurgents.  That was in 1537; the victory fell to Cosimo; and his long and remarkable reign began with the imprisonment and execution of the chief rebels.