What is "tondenhei"

The were military settler colonists recruited after the Meiji Restoration to develop and defend Japan's northern frontier in Hokkaidō against foreign nations, particularly Imperial Russia. (The term comes from ancient China, where colonist militias were also employed to defend imperial frontiers.) The first recruits in Japan were ex- samurai whose feudal lords who had opposed the Meiji forces and whose domains were therefore abolished, leaving them without gainful employment. Later recruits included commoners as well as samurai.