Assertion: knight's use | /r/Causes | gradual decline
Facets:
Source sentences:
text: The Japanese started to manufacture the Portuguese acquired matchlocks, and the use of these firearms in warfare caused the gradual decline in the use of the centuries-old lamellar armour that the samurai were known for; the Japanese armour makers started to use solid iron plates in their armour designs which were based on European armours, and eventually plate armour became the standard for samurai warriors.