When we joined the museum's National Numismatic Collection team this summer to rehouse a collection of international banknotes, we expected to come across some fascinating paper currency as we moved the notes from plastic sleeves to archival-quality folders. The tremendous breadth and variety of the collection, however, was quickly revealed to us when we came across a series of intriguing banknotes from 1930s–1940s China. Upon closer inspection, we noticed subtle (and sometimes not so subtle) differences in the notes' designs, which we discovered were actually secret propaganda messages that Chinese engravers snuck in as a way to protest Japanese occupation during World War II.

After decades of increasing its military, political, and economic influence across the Far East, Japan invaded China in 1937, initiating what is known as the Second Sino-Japanese War. The conflict continued as Europe marched into World War II. Following Japan's bombing of Pearl Harbor in 1941, China formally joined the Allied forces and continued to fight the Japanese with the help of the United States and the Soviet Union, resulting in the absorption of the Second Sino-Japanese War into World War II as part of the Pacific Theater.

During its occupation of China, Japan established a series of puppet governments (many of which printed currency) to control local populations—and whose treatment of the Chinese resulted in deep feelings of ill will toward the Japanese. One of the ways in which the Chinese promoted nationalism and boosted morale was through propaganda hidden in paper currency. The most seemingly blatant example we discovered is in a 1938 one yuan note, issued by the Federal Reserve Bank of China.

Traditionally, this note was decorated with a portrait of the renowned teacher and philosopher Confucius, in which his hands are clasped piously in prayer. The engraver of this note, however, redesigned the image to include an obscene gesture, one that was recognizably offensive in both Chinese and Japanese cultures and conveyed Chinese distaste for the Japanese that occupied the country.

Rebellious Chinese engravers also used animal symbolism to discreetly express their contempt for the puppet governments. A 100 yuan note from 1942 depicts pairs of wolf heads dispersed throughout the border of the obverse side. In Chinese culture, wolves are considered emblematic of extreme greed, particularly in reference to public officials—yet another indication of subtle defiance toward the Japanese.

Another type of animal symbolism used was the turtle, as seen in a 1940 10 yuan note that includes a series of bisected turtles along the borders of its obverse side. These animals were held in low esteem by both the Chinese and the Japanese: to call another person "a son of a turtle" was the equivalent of calling that person a bastard. Inserting these types of hidden images into the engraving plates likely provided local people with a humorous diversion from life under the new regime.

In addition to the symbolism mentioned above, Chinese engravers also hid coded messages in their propaganda banknotes. In a 50 cent note from 1940 issued by the Central Reserve Bank of China, the English letters C, G, W, R, and S can be found scattered discreetly across the ornamental border on the reverse side. Scholars believe that, once unscrambled, the letters read "Central Government Will Return Soon," a message to give hope to the oppressed people.

A second concealed message appears in a 200 yuan note, issued by the Central Reserve Bank of China in 1944. It includes the letters U, S, A, and C hidden across the obverse and reverse faces of the note. When assembled, the letters spell out the prophecy "United States Army [is] Coming," a message that angered the Japanese and resulted in efforts to have the issue recalled. This message has been attributed to the engraver Chung Kue-jen, and its discovery by the Japanese caused him to flee to Hong Kong for the duration of the war to escape punishment.

Coming across these fascinating banknotes encouraged us to delve deeper into a period of world history that we had not previously had the opportunity to explore. As we continue to organize and rehouse this vast, diverse collection of paper currency, we look forward to sharing the many interesting facts, events, and individuals we uncover with you!

Sammie Hatton and Kelly Lindberg are museum specialists with the National Numismatic Collection working on an international banknote rehousing initiative.

To learn more, check out some of the resources we consulted in writing this post: Animacies: Biopolitics, Racial Mattering, and Queer Affect (by M.Y. Chen), World War II Remembered: History in Your Hands, a Numismatic Study (by C.F. Schwan and J.E. Boling), Chinese Banknotes (by Ward D. Smith and Brian Matravers) and Outlines of Chinese Symbolism & Art Motives (by C.A.S. Williams).