 Naotora was born in Edo as the 5th son of Hori Naotada, the 11th "daimyō" of Suzaka Domain.In 1861, on the retirement of his elder brother Hori Naotake, he became "daimyō" of Suzaka.Immediately on assuming office, he removed 41 senior retainers from office, including the domain's "karō", and pursued an aggressive policy of reforms, which also include westernization and modernization of the domain's military capability.