Tiandihui

The Tiandihui, the Heaven and Earth Society, also called Hongmen (the Vast Family), is a Chinese fraternal organization and historically a secretive folk religious sect in the vein of the Ming loyalist White Lotus Sect, the Tiandihui's ancestral organization. As the Tiandihui spread through different counties and provinces, it branched off into many groups and became known by many names, including the ''Sanhehui''. The ''Hongmen'' grouping is today more or less synonymous with the whole ''Tiandihui'' concept, although the title "Hongmen" is also claimed by some criminal groups. Its current iteration is purely secular.

Under British rule in Hong Kong, all Chinese secret societies were collectively seen as criminal threats and were bundled together and defined as "Triads", although the Hongmen might be said to have differed in its nature from others. The name of the "Three Harmonies Society" (the "Sanhehui" grouping of the Tiandihui) is in fact the source of the term "Triad" that has become synonymous with Chinese organized crime. Because of that heritage, the Tiandihui (more commonly known there as "Triads') is both controversial and prohibited in Hong Kong. Provided by Wikipedia