On his way to Edo, Thunberg also obtained many Japanese coins, which he described in detail in the fourth volume of his travelogue, "Travels in Europe, Africa and Asia, performed between the Years 1770 and 1779". The coins provided new insights for European scholars into the culture, religion and history of Japan, as their possession and export by foreigners had been strictly forbidden by the shogun. This prohibition had been imposed to prevent the Empire of China and other rivals of the shogunate from copying the money and flooding the Japanese markets with forged coins.