The Wealth of Nations by Part 3 Chapter 3 Page 16

If you except Venice, for of that city the history is somewhat different, it is the history of all the considerable Italian republics, of which so great a number arose and perished between the end of the twelfth and the beginning of the sixteenth century.

In countries such as France or England, where the authority of the sovereign, though frequently very low, never was destroyed altogether, the cities had no opportunity of becoming entirely independent. They became, however, so considerable that the sovereign could impose no tax upon them, besides the stated farm-rent of the town, without their own consent. They were, therefore, called upon to send deputies to the general assembly of the states of the kingdom, where they might join with the clergy and the barons in granting, upon urgent occasions, some extraordinary aid to the king.