天台宗

Founded by 智顗 (Zhìyǐ, 538–597) on Tiantai Mountain 天台山 in Zhejiang. It was the first major fully-Sinicized school of Buddhism, organized around the Lotus Sutra and a doctrine of 'three truths in one mind' (三谛圆融). In Japan it was transmitted by Saichō in 805 as the Tendai school, parent tradition of later Nichiren and Pure Land sects.

When 天台 names this school or the Zhejiang mountain, 台 is read tāi (not tái as in 台湾 'Taiwan'). The full name 'Tiāntái-zōng' is the dictionary reading, but you will hear scholars and monks say 'Tiāntāi'.