▁The ▁n avy ▁rep elled ▁pir ates ▁using ▁an ▁advanced ▁form ▁of ▁gun pow der ▁techn ologies ▁including ▁can n ons ▁and ▁fire ▁ar rows ▁in ▁form ▁of ▁sing ije on ▁deployed ▁by ▁h wach a . ▁ ▁During ▁the ▁Japanese ▁invas ions ▁in ▁the ▁ 1 5 9 0 s , ▁Toy ot omi ▁H ide y oshi , ▁plot ting ▁the ▁con quest ▁of ▁M ing ▁China ▁with ▁Portuguese ▁guns , ▁inv aded ▁Korea ▁with ▁his ▁da im y ō s ▁and ▁their ▁troops , ▁int ending ▁to ▁use ▁Korea ▁as ▁a ▁ste pping ▁stone . ▁F action al ▁division ▁in ▁the ▁Jose on ▁court , ▁in ability ▁to ▁assess ▁Japanese ▁military ▁cap ability , ▁and ▁failed ▁attempts ▁at ▁diplom acy ▁led ▁to ▁poor ▁prepar ation ▁on ▁Jose on ' s ▁part . ▁The ▁use ▁of ▁European ▁fire ar ms ▁by ▁the ▁Japanese ▁left ▁most ▁of ▁the ▁southern ▁part ▁of ▁the ▁Korean ▁Pen ins ula ▁occupied ▁within ▁months , ▁with ▁both ▁Han se ong ▁( present - day ▁Se oul ) ▁and ▁Py ong y ang ▁captured . ▁ ▁However , ▁the ▁invasion ▁was ▁slow ed ▁when ▁Admir al ▁Y i ▁Sun - sin ▁destroyed ▁the ▁Japanese ▁invasion ▁fleet . ▁The ▁gu err illa ▁resistance ▁that ▁eventually ▁formed ▁also ▁helped . ▁Local ▁resistance ▁slow ed ▁down ▁the ▁Japanese ▁advance ▁and ▁decis ive ▁naval ▁vict ories ▁by ▁Admir al ▁Y i ▁left ▁control ▁over ▁sea ▁routes ▁in ▁Korean ▁hands , ▁sever ely ▁ham per ing ▁Japanese ▁supply ▁lines . ▁Furthermore , ▁M