The Marquis was the eighth head of the Uwajima Domain during the Late Tokugawa shogunate and a politician of the early Meiji era.
Early life
Munenari was born in Edo, the 4th son of the hatamoto Yamaguchi Naokatsu. Munenari, then known as Kamesaburō 亀三郎, was a candidate for adoption by the heirless 7th generation Uwajima lord Date Munetada because Naokatsu's father was the 5th Uwajima lord, Date Muratoki.
Clan leader
Munenari succeeded to headship in 1844. The tairō Ii Naosuke ordered Munenari's retirement in 1858. He was placed under house arrest.
He returned to prominence in the subsequent years of political maneuvering in Kyoto, as a member of the conciliatory kōbu-gattai (公武合体 union of court and bakufu) party. Late in Bunkyū 3 (1863), as a proponent of kōbu-gattai, he was made a member of the imperial advisory council (sanyō-kaigi 参与会議), together with Matsudaira Katamori and other like-minded lords.
National leader
After the fall of the shogunate in 1868, Munenari took an active role in the new imperial government; Uwajima as a domain was also deeply involved in the military campaign of the Boshin War (1868–1869).
Munenari was a crucial figure in Japan's international relations during the early Meiji period. In 1871, representing the Japanese government, he signed the Sino-Japanese Friendship and Trade Treaty with Li Hongzhang, a viceroy of Qing Dynasty China.
Also in 1871, the han system was abolished in Japan, and he was able to fully cut his political ties to Uwajima. In 1881, Munenari entertained King Kalākaua, of the Kingdom of Hawaii, on the first state visit to Japan of an actual head of state in its recorded history. He was first created a count in the new peerage system, but was later promoted to marquess.
Munenari died at Imado in Tokyo in 1892, at age 75.
Gallery
File:Sino Japanese Friendship and Trade Treaty 13 September 1871.jpg|Sino-Japanese Friendship and Trade Treaty, 13 September 1871. The treaty was signed in Tientsin, by Date Munenari and Li Hongzhang
File:Uwajima Date Togakuji Cemetery 12.JPG|Tomb of Date Munenari (right) in Uwajima (宇和島 等覚寺)
File:Take ni Suzume.svg|The emblem (mon) of the Date clan
伊達宗城（，1818年9月1日 - 1892年），日本江戶時代末期大名、明治時代時期政治家。宇和島藩第八代藩主（1844年-1858年）。官位從四位下、遠江守、侍從。明治時代封伯爵。