The merchants were the true masters of the Renaissance when they accumulated the wealth with
which artists, scholars and humanists were supported, with which the great art of these florishing
times was nurtured.
The Italian city states profited from Italys location in between Christian Europe and the Orient, between the West and the Byzantine Empire, from its connections to almost every known spot of the world. Their merchants could be found everywhere, on the markets of Sweden and the fairs of the Barbary States, in Spain and in the Ottoman Empire, in Russia, China and India. Not only did they sell their own produce but they also traded the manifold goods from foreign countries. In constant contact with foreign cultures and customs they lost their medieval narrowmindness and brought home a truly worldy tolerance.
So it isn't much of a surprise that the merchants were organized in the Arti Maggiori, the big guilds, together with bankers, important manufacturers, lawyers, judges, doctors and other members of the upper classes - the Popolo grasso. They had the money and in the Italian cities states of the Renaissance, money equalled power.