While traditionally many historians believed that the art of Chinese papermaking had been transmitted to Europe via Arab merchants who got the secret from prisoners of war taken at the Battle of Talas, some believe that Jewish merchants such as the Radhanites were instrumental in bringing paper-making west. Joseph of Spain, possibly a Radhanite, is credited by some sources with introducing the so-called Arabic numerals from India to Europe. Historically, Jewish communities used letters of credit to transport large quantities of money without the risk of theft from at least classical times. This system was developed and put into force on an unprecedented scale by medieval Jewish merchants such as the Radhanites; if so, they may be counted among the precursors to the banks that arose during the late Middle Ages and early modern period.