Lifespan: Tenbun 6 (1537) to 7/10 of Bunroku 3 (1594)
Other Names: Tsuruchiyomaru (childhood), Magijirō/Magoshirō (common), Nobutaka
Rank: bushō, sengoku daimyō
Title: Junior Fourth Rank (Lower), Master of the Eastern Capital Office
Clan: Date → Iwaki
Father: Date Harumune
Adoptive Father: Iwaki Shigetaka
Mother: Kubohime (daughter of Iwaki Shigetaka)
Siblings: Chikataka, Onamihime (formal wife of Nikaidō Yoshimasa), Date Terumune, Rusu Masakage, Ishikawa Akimitsu, Kokubun Morishige, Sugime Noamune, Kyōseiin (formal wife of Date Sanemoto), 益穂姫 (wife of Koyanagawa Morimune), Hikohime (formal wife of Ashina Morioki → formal wife of Ashina Moritaka), Hōjuin (formal wife of Satake Yoshishige)
Wife: Keijuin (daughter of Sataki Yoshiaki)
Iwaki Chikataka served as a bushō and sengoku daimyō during the Sengoku and Azuchi-Momoyama periods. He was the sixteenth head of the Iwaki clan and uncle of Date Masamune.
Chikataka was born as the eldest son of Date Harumune of Mutsu Province. In connection with a battle in 1534, based on an agreement between his father, Harumune, and maternal grandfather, Iwaki Shigetaka, Chikataka became the adopted heir of Shigetaka and successor to the Iwaki clan. In 1569, after the death of his adoptive father, Shigetaka, Chikataka inherited the headship of the clan.
While there are accounts of small-scale military operations including encroachments on the territory of the neighboring Tamura and Ishikawa clans and a deployment to assist Nikaidō Moriyoshi, Chikataka primarily maintained a focus on diplomacy begun by Shigetaka. He served as a mediator for the conflict in the Date clan between his father, Harumune, and younger brother, Date Terumune. He also facilitated a settlement between the Date and Ashina clans in regard to the course of action regarding the Nikaidō clan. Based on letters exchanged with his uncle, Date Sanemoto, regarding worries with respect to the relationship between Harumune and Terumune, he placed an emphasis on his own relationship with the Date clan.
From the era of Satake Yoshiaki, the Satake clan of Hitachi Province advanced into Mutsu seeking to subordinate the Ishikawa and Shirakawa-Yūki clans. From the era of Shigetaka, a formerly friendly relationship between the Satake and Iwaki clans gradually deteriorated. Even though Chikataka received the daughter of Yoshiaki as his wife, relations did not improve. From 1568 to 1571, in the midst of frequent clashes with the Satake clan, Shigetaka died of illness and the subsequent movements of Chikataka soon became unknown. Thereafter, Chikataka’s wife who originated from the Satake clan acted as a proxy for the head of the Iwaki clan and Yoshiaki’s son, Satake Yoshishige, intervened in the affairs of the Iwaki clan so it is surmised that an incident occurred in the Iwaki family around this time but details are unknown. Under one theory, Chikataka went mad from illness and became unable to fulfill his duties as the head of the clan.
Around 1578, Chikataka’s son, Iwaki Tsunetaka, became the head of the clan while Chikataka’s wife served as a guardian. According to historical records, Chikataka was living until 1594.