Florence had a revival of commerce around the year 1000, and grew in strength and achieved a virile dignity by adpting an urban way of life which brought it into violent conflict with the agrarian forms identified with the feudal age. The florentine woolen industry was the leading source of national prosperity, but above the gilds completely dictated the pattern of the city's material activity. Florence owed its greatness to its vigourous economic forces, yet through two leading centuries it was nother other than a democray of 21 constitutive gild units. (I shall not go into the gilds here, as they are government issues.)
The communal movement was prompted by the renewal of the broken ties between the backwrd west and and the more advanced east med. Early on it was the Byzabtine connection with aided florence in its distribution of goods and trade. The stimulation of local crafts , which were energetic in developing a manufacturing specialty and which had an advantage in the matter of raw products, forged ahead of their neighbours. Florence was one of these and became the metropolis of Tuscany. It should, however, be said that Florenec was economically inferior to Pisa and even Lucca.
It was the feud between the two leading Tuscan communities which gave Florence an opertunity to expand. When Pisa called for help, in this feud, Florence was the first to supply an answer, and aided it experditions as land-locked Florence had an eye opn Pisa's sea-born trade. The economic milestone was the privilgies given to Florence by Pisa. The first of them was the Pisa silver penny, as if Florence put its backing behind it, it would get half of the profits of the pisa mint. Secondly, Pisa promised to carry Florentine citizens and their goods across the water, so eliminating Florences lack of sea trade. Finally, shore tolls were reduced for Florentines to lower than that given to pisans themselves.
Florence enjoyed these concession for half a century without break, and this alliance of 1171, was the major factor in the rise of Florentine fortunes. It was also the siegeing of the Eternal City, when Florence made the maritime town into a dependence which would become the serviceable instrument of Florentine commercial expansion.
Trade routes, goods exchanged, money and merchant companies all expanded in this period. It can be said that it was the merchant gilds which gave Florence its expansion and prosperity, as they achieved close to a stable government as was possible and they siezed power in 1282. It was also these gilds which successfully captured the rapidly multiplying economic opportunities of the C13th and made Florence a leading focus of Italian and World trade.