Complex sentence: In reaction to the Great Genroku earthquake in "Genroku" 16, the era name was changed to "Hōei" (meaning "Prosperous Eternity"), commencing on the 13th day of the 3rd month.
Split into simpler sentences: In reaction to the Great Genroku earthquake in "Genroku" 16, the era name was changed to "Hōei" (meaning "Prosperous Eternity"). The previous era ended and the new one commenced in "Genroku" 17, on the 13th day of the 3rd month.