Medici, Cosimo I de', called the Great 1519-74
Florentine politician

Duke of Florence from 1537 and Grand Duke of Tuscany from 1569, he possessed the astuteness of his greater predecessors, but was cruel and relentless, though one of the ablest rulers of his century. A skilled soldier, he annexed the republic of Siena in 1555 and doubled the territory of Tuscany during his rule. He devoted his energies to developing the trade, agriculture and economic infrastructure of Tuscany, and to building up its armed forces. At the same time, he was a notable patron of artists and a great collector of Etruscan antiquities.