The trident has great meaning and symbolism for the Mongolic peoples, the symbol and instrument may have been adapted for use by the Japanese as a fishing and marine instrument from early times either by cultural diffusion and borrowing from the North, or perhaps there may have been some limited demic diffusion in the Northern or Northeastern coasts.
Source: Chinggish Khan: Ancestor, Buddhist or Shaman? by Isabelle Charleux
…in the seven Ordos banner to represent the main one as ambassadors).28
Fig. 3. Detail of the main deity, Nine Dayicing Tngri (Tib. dGra lha), thangka, painting on silk, Mongolia, nineteenth century, 51×34 cm. © Ferenc Hopp Museum, Budapest, Inv. No. 72.16.
The trident on top of Chinggis Khan’s helmet has several possible meanings. In
Buddhist iconography, the trident (sesum, < Tib. rtse gsum) symbolizes the Three Jewels (the Buddha, the Dharma and the Sangha), but was later interpreted by Mongols as the symbol of fire (erdeni γal, γurvan üjügürtei γal).29 Modern artists depicting Chinggis with this symbol above his head obviously refer to fire, not to the Three Jewels. But the trident is also an obvious reference to the top of Chinggis Khan’s white standard. A trident is visible on top of the topknot or helmet of several warrior deities in the Mongolian world, such as the Nine Dayicing Tngri (Tib. dGra lha),30 who are connected with the sülde (soul) of Chinggis Khan.31 In fig. 3 for instance, the trident with horse-tail is clearly seen on top of the deity’s helmet.32 This attributed will be repeated in some modern portraits. (fig. 12) 28 Since Saγang Secen’s standard is topped by a trident, (Mostaert 1957: 548-50 n. 37) the banners depicted here are more probably Chinggis Khan’s black standard.
29 Since the ‘fire motive’ was found on old rock carvings, Mongols now believe that it is a very ancient Mongol symbol, and its Buddhist origin was forgotten: the three flames are said to represent the past, the present and the future.
30 Medieval helmets were often topped by a pointed pike and decorated with horse-tail. See a fourteenth century helmet in the National Museum of Mongolian History, Ulaanbaatar.