Cosimo selected this site, in what was then the Via Larga but is now the Via Cavour, partly because his father had once lived there, and partly because it was close to S.Lorenzo, which his father, with six other families, had begun to rebuild, a work he intended himself to carry on.
The palace was begun in 1430 abd was still in progress in 1433 when the Albizzi, who had always viewed the rise of the Medici family with apprehension and misgiving, and were now strengthened by the death of Niccolo da Uzzano, who, though powerful, had been a very cautious and temperate adviser, succeeded in getting a majority in the Signoria and passing a sentence of banishment on the whole Medici tribe as being too rich and ambitious to be good citizens of a simple and frugal Republic.

Cosimo therefore, after some days of imprisonment in the tower of the Palazzo Vecchio, during which he expected execution at any moment, left Florence for Venice, taking his architect with him.

In 1434, however, the Florentines, realizing that under the Albizzi they were losing their independence, and what was to be a democracy was become an oligarchy, revolted, and Cosimo was recalled, and, like his father, was elected gonfalonier.

With this recall began his long supremacy; for he returned like a king and like a king remained, quickly establishing himself as the leading man in the city, the power behind the Signoria.

Not only did he never lose that position, but he made it so naturally his own that when he died he was able to transmit it to his son.
Cosimo de' Medici was, I think, the wisest and best ruler that Florence ever had and ranks high among the rulers that any state ever had.