competitive with Florentine manufactures were excluded from the              
markets of Florence through protective tariffs set by a government           
of merchants and financiers.                                                 
    To finance this industry and commerce, and much else, the eighty           
banking houses of Florence- chiefly the Bardi, Peruzzi, Strozzi,             
Pitti, and Medici- invested the savings of their depositors. They            
cashed checks ( polizze ), `05033 issued letters of credit ( lettere         
di pagamenti ), `05034 exchanged merchandise as well as credit, `05035             
and supplied governments with funds for peace or war. Some                   
Florentine firms lent 1,365,000 florins ($34,125,000?) to Edward III         
of England, `05036 and were ruined by his default (1345). Despite such       
catastrophes Florence became the financial capital of Europe from            
the thirteenth through the fifteenth century; it was there that              
rates of exchange were fixed for the currencies of Europe. `05037 As                 
early as 1300 a system of insurance protected the cargoes of Italy                     
on their voyages- a precaution not adopted in England till                   
1543. `05038 Double-entry bookkeeping appears in a Florentine                
account book of 1382; probably it was already a century old in               
Florence, Venice, and Genoa. `05039 In 1345 the Florentine                   
government issued negotiable gold-redeemable bonds bearing the low           
interest rate of five per cent- a proof of the city's reputation for         
commercial prosperity and integrity. The revenue of the government           
in 1400 was greater than that of England in the heyday of Elizabeth.         
    The bankers, merchants, manufacturers, professional men, and skilled       
workers of Europe were organized in guilds. In Florence seven guilds         
( arti,  arts, trades) were known as  arti maggiori  or greater              
guilds: clothing manufacturers, wool manufacturers, silk goods               
manufacturers, fur merchants, financiers, physicians and druggists,          
and a mixed guild of merchants, judges, and notaries. The remaining          
fourteen guilds of Florence were the    arti minori  or minor trades:          
clothiers, hosiers, butchers, bakers, vintners, cobblers, saddlers,          
armorers, blacksmiths, locksmiths, carpenters, innkeepers, masons            
and stonecutters, and a motley conglomeration of oil sellers, pork           
butchers, and ropemakers. Every voter had to be a member of one or           
another of these guilds; and the nobles who had been disfranchised           
in 1282 by a bourgeois revolution joined the guilds to regain the            
vote. Below the twenty-one guilds were seventy-two unions of