Ieyoshi was utterly surprised and unprepared upon receiving word of the arrival of Matthew Perry's ships in Edo Bay.[1] Whether from shock or from some other cause, Shogun Ieyoshi soon began to feel very sick and died shortly afterwards.
^The American naval expedition planners did have the forethought to incorporate reference material written by men whose published accounts of Japan were based on first-hand experience. J.W. Spaulding brought with him books by Japanologists Engelbert Kaempfer, Carl Peter Thunberg, and Isaac Titsingh. Screech, T. (2006). Secret Memoirs of the Shoguns: Isaac Titsingh and Japan, 1779-1822, p.73.