It became a general university of Buddhism, spreading the teachings of Tendai Hokke, as well as esoteric Buddhism, Zen (meditation), and Nenbutsu, and in the Heian period gained the support of the Imperial Household and nobles, thereby becoming quite powerful.
天台法華の教えのほか、密教、禅（止観）、念仏も行なわれ仏教の総合大学の様相を呈し、平安時代には皇室や貴族の尊崇を得て大きな力を持った。