- Birth: 1836/12/19
- Death: 1883/11/12
- Birth Name: 島津敬子 (Shimazu Sumiko)
- Married Name: 徳川 篤姫 (Tokugawa Atsu-hime)
- Retired Name: 天璋院 (Tenshô-in)
Atsu-hime  was born the daughter of Shimazu Tadatake (島津忠剛), the head of a branch of the powerful Shimazu family, that of the lords of the Satsuma fief of southern Kyushu. She was adopted by the lord of the fief, Shimazu Nariakira and given the name Atsu. Adopting the daughter of a branch house or a high-ranking retainer for use in marriage politics was not an unusual practice in Japan; it was much used by Tokugawa Ieyasu, among others. In Atsu's case, Nariakira intended to marry her to the shogun Tokugawa Iesada. However, Nariakira's purpose was not to become the grandfather of the future shogun. Iesada had already buried two wives and was still childless. His successor had to be chosen from amoung the heads of several Tokugawa branch houses. The most natural one was his cousin, the young lord of Kii Iemochi (1846-1866). However, Yoshinobu (1837-1913), originally of the Mito Tokugawa clan, but adopted into the Hitotsubashi branch, was also a strong candidate. The latter was supported by those, including Nariakira, who believed the shogunate needed a strong leader who could make necessary reforms, especially in view of the foreign threat typified by the visit of Matthew Perry in 1853. It was hoped that Atsu could be influential in getting Yoshinobu named as successor. The "outer lords," (Tozama Daimyo) including the Shimazu, had been shut out of the shogunate administration since the beginning, but from the shogunate side it was hoped that this marriage would strenghten the weakening shogunate with this powerful clan.
As the wife of the shogun was supposed to be from the imperial family or from a high-ranking imperial noble (Kuge) family, Atsu was adopted by the Minister of the Right, Konoe Tadahiro. Her wedding palanquin, today in the collection of the Smithsonian Institution, bore the Tokugawa and Konoe family crests, part of the elaborate gold leaf decorations on a black lacquered exterior; meanwhile, painted panels on the inside depicted scenes from the Tale of Genji. Then in the 11th month of 1856, she entered Edo Castle as the wife of the shogun. The next year she was formally given the title of Mi-dokoro, the wife of the shogun.
However, Atsu was not able to exercise the influence that had been hoped. Iesada died in the 7th month of 1858, naming as his heir the young lord of Kii. Two months after her husband's death Atsu-hime retired and took the name Tenshô-in, and at the end of the year was given Third Degree rank. She remained living in Edo castle during the shogunate of Iemochi and that of Yoshinobu, who became shogun in 1866.
During this time, the Satsuma clan joined forces with the Chôshû clan in support of the imperial restoration against the shogunate, and events eventually erupted into the Boshin War (1868), ending with the overthrow of the shogunate. At the end of the war, Tenshô-in (Atsu), who was from Satsuma, and Seikan-In-no-Miya (静寛院宮) (formerly Kazu-no-Miya 和宮), the widow of Shogun Iemochi and the daughter of Emperor Ninkô, successfully interceded with the victors for the continuance of the Tokugawa family. After the fall of Edo Casle, Tenshô-in and the rest of the Tokugawa family were deprived of their rank. After vacating Edo Castle at the age of 34 on 10d 4m 1868, she moved into the Hitotsubashi mansion and stayed there until the 28d 7m, then settling in the mansion of the Kii Tokugawa in the Akasaka (赤坂) district of Edo/Tokyo. She then moved to Ushigometoyama (牛込戸山) in Tokyo on 11d 8m 1870. Yet in 1872, to better help supervise the raising and education of Yoshinobu's heir Yasuda Kamenosuke (安田亀之助) (Tokugawa Iesato 徳川家達), she moved back to Akasaka, settling in Fukuyoshi-chô (福吉町), where she remained until Iesato went to study abroad in England in 1877. After that, she moved into the main Tokugawa residence in Sendagaya, in the Shibuya district of Tokyo. Tenshôin suffered from Parkinson’s disease, which eventually took her life at the age of 49 in 1883. Upon her death her rank was restored.
- "Hime," often translated "princess," is a title used with the personal name of a woman of high rank, such as the daughter of a daimyo.
- A similar route had been chosen when a woman from the Shimazu family (Kôdai-In 広大院) married the 11th shogun Tokugawa Ienari. In that case, they had been engaged before he was chosen as shogun. One of Kôdai-In's names was Atsu-hime.
- "The Princess Atsuhime's Wedding Palanquin Revealed in the Smithsonian's Arthur M. Sackler Gallery. ArtDaily.org. 3 November 2008.
Atsu-hime in Fiction
- Tenshôin Atsuhime (天璋院篤姫) ANB 1985
- Atsuhime (篤姫) NHK 2008
- Tenshôin Atsuhime (天璋院篤姫) Miyao Tomiko
- Tenshôin Sumiko (天璋院敬子) Umemoto Ikuko
- 明治維新人名辞典, 日本歴史学会編集、吉川弘文館, 1981 (Dictionary of Personal Names of the Meiji Restoration).
-  From Japanese Wikipedia 広大院 (Kôdai-In)
- 天璋院篤姫, ＮＨＫプロモーション, 2008 (Catalog from the Tenshôin Atsuhime Exihibit, Edo-Tokyo Museum)
- Beerens, Anna."Interview with Two Ladies of the Ooku: A Translation from Kyûji Shimonroku", Monumenta Nipponica Vol. 63:2(2008) pp. 265-324.