Zhou Dunyi
Zhou Dunyi had two students who made major contributions to Confucianism: his nephews Cheng Yi and Cheng Hao. The Cheng brothers studied under Zhou Dunyi only for a short time when they were younger. The brothers moved on to establish the Cheng-Zhu School, which dominated Chinese philosophy for over 700 years. Zhou Dunyi is considered the founding father of that school although there are no references in the Cheng brothers' writings to his contributions.