This membership certificate of the Tsung Sin Kongsi, a Chinese secret society in Singapore that emerged from the Tiandihui (Heaven and Earth Society) has upon it the impression of the three Hong coins. The characters on the obverse of the coins demonstrates that such coins were only issued for internal use, unlike the copper coins that were in general circulation. On the bottom left corner of the certificate are the characters jin lan qun (pledged brothers) which refer to the pledged brothers of the Obedience Hall of the Hong society. Secret societies in Singapore were set up in the 19th century with increased Chinese migration to the British colony to provide mutual aid and support for the migrants. These societies had originated from the Tiandihui, which in turn was a local version of the secret society in China that was a sworn fraternity of men with the common aim of overthrowing the Qing dynasty and restoring the Ming. Various splinter groups (hui or kongsi) subsequently emerged among the main dialect groups.
