English: The 'secret formation,' a predecessor of Qi Jiguang's Mandarin Duck formation. The five man team consists of a leader who wielded a shield, a man wielding a wolf brush, and three pikemen. 'Secret formations' were deployed on flat terrain in large blocks so that the shieldmen and wolf brush soldiers protected the pikemen from arrows and melee weapons.
Date
Source
Great Ming Military, scan from " the training manuals found in 'Ji Xiao Xin Shu (《紀效新書》)'"
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