century (100 years)

fortress walls; town walls (walls surrounding a fortress or town)

an invasion

invade, militarily go into

century

an enemy / revenge, vengeance / opponent (of the game or conflict) / (archaic, obsolete) marriage partner

護る: to protect, to defend / to watch carefully / to abide (by rules), to observe (regulations)

(archaic) to stand watch over something, to be on the lookout for something (such as a watchman controlling entry to a place) / (archaic) to protect or defend something, to ensure that something is safe

(Classical Japanese) to be watching continuously, to be on watch repeatedly, to be on look out / (Classical Japanese) to protect something, to take care of something

(Classical Japanese) to be watching continuously, to be on watch repeatedly, to be on look out / (Classical Japanese) to protect something, to take care of something