[2] After studying at the Meirinkan clan military academy, he entered the Kiheitai irregular militia of the Chōshū domain and played an active role in the Boshin War to overthrow the Tokugawa shogunate.

[3] In 1884, he accompanied Ōyama Iwao on a tour of Europe, to study the military systems in various western countries, and favoured an army organisation modelled after the French, and on his return became commander of the Tokyo Garrison.

Miura was increasingly concerned over growing Russian influence over the Korean government, and less than a month after his arrival in Korea, Empress Myeongseong ordered the disbanding of the Japanese-trained Hullyeondae militia.

[3] Miura then staged a counter-coup, assassinating the Empress; however, this plan backfired due to international outrage over the incident, widespread anti-Japanese violence throughout Korea, the arrest of pro-Japanese government officials and King Gojong seeking shelter in the Russian consulate.

[5] Later, after the Japan–Korea Annexation Treaty in 1910, Miura became a privy council member and focused on eliminating vestiges of the clan-based factionalism from politics, gaining a reputation as an Éminence grise for fixing issues "behind-the-scenes".