Iron Armor of the Korean Peninsula

Timeline

1. c. 1–200Northern Korean Peninsula · Korean PeninsulaFrom the 1st to 2nd centuries CE, iron output increased among the states of the Korean Peninsula; lamellar armor laced from iron plates and iron helmets appeared, and Goguryeo cavalry began to be distinguished from surrounding powers by their iron armor, engaging in military contact with the Eastern Han, Xianbei, and others.
2. c. 200–400Guonei City · Jilin ProvinceIn the 3rd to 4th centuries CE, Goguryeo's iron cavalry became renowned for both men and horses being clad in heavy armor; the Book of Wei states that Goguryeo's terrain was of extreme mountains and precipices, its people brave and skilled in riding and archery, with armored horses, and iron-armored cavalry became the core military force for expansion and defense.
3. c. 400–500Korean Peninsula · Korean PeninsulaIn the 5th century CE, Baekje and Silla also developed iron-armored troops; the three kingdoms clashed with heavy cavalry in the Han and Nakdong river basins; Baekje's iron armor and manufacturing techniques were transmitted to Japan via diplomatic missions, influencing military equipment in the Wa state's Kofun period.