The formation of bujutsu ryūha [martial arts schools] was underpinned by Japanese cultural traditions. Progressing towards mastership required sustained training of body and mind. The process of instruction and learning in geidō or the “ways of artistic performance arts” focused on the practice and demonstration of kata (prearranged formal patterns of movements). Kanō Jigorō (1860-1938), the founder of Kōdōkan jūdō, considered the theory behind the kata of Kitō-ryū ―a 17th century Japanese martial arts school― as “extremely complex” and well developed. He decided to preserve Kitō-ryū’s yoroi kumi-uchi-no-kata in Kōdōkan jūdō’s under the name koshiki-no-kata [Forms Antiques]. This PhD study seeks to make a qualitative contribution to the comprehension of the Kitō-ryū school and its influence on Kōdōkan jūdō‘s foundations and curriculum as these took shape in the Meiji and Taishō era, and under the secularizing influences of jūdō’s ‘Versportlichung’. Jūdō, after the death of Kanō in 1938, continued to transform into an Olympic competitive sport at the detriment of its educational objectives. Important self-defense and conceptual exercises in the form of kata today are practiced as a mere modernist cultivation of ishinhō or aesthetics. My research questions pertain to: (1) what information do the historic primary sources contain about the foundations, genealogy, curriculum and objectives of Kitō-ryū ? (2) What curricular material of Kitō-ryū is incomplete or lost and to what extent can it be restored ? (3) What were Kanō Jigorō’s objectives by retaining in full Kitō-ryū’s koshiki-no-kata and how does that knowledge practically affect the principal of maximal efficiency ? (4) What were the effects of the Meiji restoration and Shōwa modernism on jūdō’s historic curricular development and Kanō’s objective of ishinhō ? These questions are best explored by a qualitative approach that presents a holistic multi-method framework able to devote considerable attention to epistemological criteria. We have chosen for a mixed hermeneutic phenomenological and hermeneutic philological method, in order to unravel meanings that may not be immediately apparent. The method will be applied to textual analyses of primary and secondary sources and historical artefacts (mainly 18th century to pre-Shōwa period). Texts will be read from a postmodern interdisciplinary angle, where the role of the researcher is ‘re-conceptualized’ or ‘de-centered’. An interpretivist framework is compatible with both an historical as well as a post-modern analytical framework. Texts written in often unpunctuated classical Japanese that contains obsolete alternative hiragana and sometimes cursive script will be first converted into a “diplomatic transcription” that contains the original text converted into contemporary Japanese kanji with furigana added where appropriate, an English translation, and eventual linguistic notes. Despite the small available body of research on Kitō-ryū in Japanese there exist no known available translations ―annotated or other― of the densho (secret archival records) of Kitō-ryū, nor, are there any critical analytical studies that allow us to address the above questions. Therefore, this dissertation through philological and historical analysis of rare historic manuscripts, historic texts and other media, offers an important contribution that is predicted to have implications on our understanding of Kitō-ryū and of the current Kōdōkan jūdō curriculum and foundations. It will also represent the first critical scholarly study of this topic.