Already at the turn of the thirteenth century the ability to read, write and keep accounting books was outright indispensable among all the professions in the towns of Prussia for the correct functioning of municipal administration and among the merchants and artisans. Those requirements contributed indirectly to a relatively rapid development of mediaeval town schools and the inclusion into their curriculum of elements of teaching practical skills. The fact that at this time the oldest group of preserved official town books from Europe are sources pertaining to the fiscal activity of the councils and their offices testifies to the great role and significance of bookkeeping in the economic and social life of particular towns in the discussed territory. Material of this sort occurred in all mediaeval towns, regardless of the sort of law upon whose basis the latter were located. There appeared a parallel need for noting down assorted trade and financial operations conducted by private persons. Bookkeeping of this variety emerged already in the thirteenth century in Venice, Genoa and the towns of north Italy, and subsequently was adopted in other European trade centres. Models of such bookkeeping came to Poland not directly from Italy but through the intermediary of German towns from which a considerable part of the local merchants arrived. For all practical purposes, until the sixteenth century so-called single entry bookkeeping predominated. Initially, accounts were kept by town chanceries, counting houses or workshops with the help of records using Roman numerals; Arabian counterparts were not introduced until the second half of the fifteenth century.