Phajo Drugom Zhigp from Ralung in Tibet was instrumental in introducing yet another school of Buddhism – the Drukpa Kagyu sect. In 1222 he came to Bhutan, an event of great historical significance and a major milestone for Buddhism in Bhutan, and established the DrukpaKagyi sect of Buddhism, the state religion. His sons and descendants were also instrumental in spreading it to many other regions of western Bhutan.