Tsukiyama-dono was a lady who lived in Japan during the Sengoku and Azuchi-Momoyama periods.
Tsukiyama-dono (or Lady Tsukiyama) was the formal wife of Tokugawa Ieyasu. Her real name was Sena or unidentified. Her common name was Senahime. She was generally called Tsukiyama-dono, Tsukiyama-gozen, or Suruga-gozen. The term “Tsukiyama” originated from the place name of the city of Okazaki.
Tsukiyama-dono was the daughter of Sekiguchi Chikanaga, a powerful retainer of the Imagawa clan. Her mother was the aunt or younger sister of Imagawa Yoshimoto. If her mother was the younger sister of Yoshimoto, then Tsukiyama-dono would have been his niece. There are various theories concerning her age, including that she was the same age as Tokugawa Ieyasu, that she was two years older, or that she was almost twelve years older (an entire sexagenary cycle). According to genealogical records, she was the granddaughter of Ii Naohira and first became a consort of Yoshimoto and, later, as an adopted younger sister, wed Chikanaga. In that case, she would have been a cousin of Ii Naomori and the child of a cousin of Ii Naotora.
There are theories that refute a marital relationship between Sekiguchi Chikanaga and the Imagawa clan, asserting the misattribution to Chikanaga’s older brother, Sena Ujitoshi, who wed the older sister of Yoshimoto. The Sekiguchi had the pedigree of a family member of the Imagawa clan. The Imagawa were, in turn, an illegitimate branch of the Kira clan holding rights of succession to the supreme shōgun with a status in the Muromachi bakufu above the family of the kanrei, or deputy shōgun. If Ieyasu (at the time known as Matsudaira Motonobu, then Matsudaira Motoyasu) wed a daughter of the Sekiguchi as members of the Imagawa clan, then he would have had a status corresponding to members of the Imagawa.
On 1/15 of Kōji 3 (1557), Tsukiyama-dono wed Matsudaira Motonobu who had been residing in Sunpu as a hostage of the Imagawa clan. In 1559, she bore Takechiyo (Matsudaira Nobuyasu) and, in 1560, Kamehime.
On 5/19 of Eiroku 3 (1560), at the Battle of Okehazama, her uncle, Imagawa Yoshimoto, was killed. Thereafter, Motoyasu (changed from Motonobu) returned to Okazaki. In the third month of 1562, Ieyasu (changed name from Motoyasu) met with Oda Nobunaga and then entered into an alliance with him. This stirred the anger of Imagawa Ujizane toward her father, Chikanaga. As the father-in-law of Ieyasu, Chikanaga took responsibility and, together with his formal wife, ended their lives.
Ishikawa Kazumasa, a daimyō and close associate of Tokugawa Ieyasu, persuaded Imagawa Ujizane to accede to a demand from Ieyasu to release Tsukiyama-dono and her children in exchange for the return of Udono Ujinaga and Udono Ujitsugu (siblings) who were captured during an assault by Tokugawa forces on Kaminogō Castle. Thereafter, Tsukiyama-dono and her children departed the Imagawa residence and went to Ieyasu’s base in Okazaki. Instead of Okazaki Castle, however, she resided outside of the castle at the Seigan Temple. Moreover, in one account, rather than referring to her as Gozen-sama to indicate a formal wife, she is referred to as Nobuyasu-okaka-sama, or the mother of Nobuyasu, suggesting that after departing from the Imagawa she was divorced from Ieyasu.
In 1567, her son Nobuyasu and Oda Nobunaga’s eldest daughter, Tokuhime, married at the mutual age of nine. In 1570, when Nobuyasu, as the lineal heir, moved to Okazaki Castle, Tsukiyama-dono entered the castle as the natural mother of the heir.
Ieyasu moved to Hamamatsu in Tōtōmi Province, but Tsukiyama-dono and Nobuyasu remained in Okazaki. Tokuhime bore two daughters – Tokuhime in 1576 and Kumahime (Myōkōin) in 1577. Tokuhime (Nobuyasu’s wife) could not bear a son, causing worry for Tsukiyama-dono. Tsukiyama-dono then invited as resident consorts for Nobuyasu the daughter of Asahara Masatoki (a former retainer of the Takeda family who later became a retainer of the Tokugawa) and the daughter of Hinata Tokimasa.
In 1579, Tokuhime sent to Nobunaga a letter setting forth twelve claims against Tsukiyama-dono, including, among others, that Tsukiyama-dono: (i) had slandered her to Nobuyasu, (ii) was engaged in an affair with a Chinese physician named Genkyō, and (iii) was colluding with the Takeda family. Upon this basis, Nobunaga ordered Ieyasu to execute Nobuyasu. Ieyasu then ordered the execution of his wife. On 8/29, she was pressured by Okamoto Tokinaka and Nonaka Shigemasa (who feared for the future of the Tokugawa family) to take her own life near Lake Sanaru in the village of Koyabu in the Fuchi District of Tōtōmi. When she resisted, they decapitated her instead. Following an examination by Ishikawa Yoshifusa, her head was sent to Nobunaga at Azuchi Castle. Approximately two weeks later, on 9/15, Nobuyasu committed seppuku at Futamata Castle.
Her remains were buried at the Seirai Temple on Mount Takamatsu in Hirosawa in the Naka ward of the city of Hamamatsu. A burial mound for her head was made at the Yūden Temple in the city of Okazaki in Aichi Prefecture. Later, around the Tenpō era (1830 to 1844), the grave was moved to the Hachiōji Shrine.
Mystery of her killing
Many questions remain in regard to the events that transpired. There is no evidence in authenticated sources that Tsukiyama-dono was, for example, colluding with the Takeda clan, having an affair with Genkyō, or making Nobuyasu an accomplice in crime. This suggests the claims made by Tokuhime against her were false accusations. Owing to the absence of justifiable grounds for her execution, a reason was crafted based on the assertion that she was killed to prevent her from engaging in mad acts after learning of the expected death of Nobuyasu. Alternatively, Ieyasu was troubled by the conflict between mother and son on one side and Tokuhime on the other so he made clear that they must take responsibility for allowing the difficult situation to escalate. Another theory is that the murder of Tsukiyama-dono and suicide of Nobuyasu were the result of tensions between Ieyasu and Nobuyasu. While Nobuyasu and Tokuhime initially got along well, after she bore two girls, the relationship appeared to falter. Drawing from letters and diaries during this time, it can be surmised that Ieyasu attempted to restore their relationship and, around this time, when Nobunaga came to Okazaki for a falconry expedition, he may have also endeavored to address the situation. Finally, there is a theory that the band of retainers under Nobuyasu splintered among one faction who backed Nobuyasu and desired to rebel against Ieyasu, a faction who obeyed Nobuyasu but remained loyal to Ieyasu, and yet another faction who had misgivings about Nobuyasu’s abilities and resented him, leading to conflict and the purging of members of the clan.