historian (d. 870) Ida of Herzfeld, Frankish duchess and saint (approximate date) Li Zaiyi, general of the Tang Dynasty (d. 837) Methodios I, patriarch of Constantinople (or 800) Deaths September 23 – Ælfwald I, king of Northumbria Abd al-Rahman I, Muslim emir of Córdoba (b. 731) Adalgis, king and co-regent of the Lombards Hnabi, duke of the Alemanni (approximate date) Mauregatus, king of Asturias (or 789) Mazu Daoyi, Chinese Zen Buddhist monk (b. 709) Ōnakatomi no Kiyomaro, Japanese nobleman (b. 702) References Sources