The number of such tribes has varied from three to twenty-three, depending on the time period and the criteria used by the classifiers. All of these peoples share a Malayo-Polynesian linguistic base, split into various dialects. These linguistic sub-groups differ according to the geographic origin of a particular migratory wave and the subsequent isolation or assimilation of the settlement over thousands of years. For this brief consideration of edged weaponry, a division of the peoples according to their geographic placement on the island would be convenient. The main island of Formosa may be divided into Northern, Central, and Southern territories.
Knives are important tools and male costume accessories in all three areas.
Certain characteristics distinguish those made and used in each region. Most blades curve slightly upwards towards the tip, this feature being more prominent in the Northern and Central groups. The knives illustrated here are of the Baiwan people, who inhabit the south-central mountains and the southern foothills of Formosa. The blades are typically straight, in marked contrast to the curved styles from more northerly areas. The blades are secured to the hilts via a long tang which is bent over and hammered tight against the pommel, which is usually a flat metal plate.