Choe Chiwon (tɕʰʷe tɕʰiwʌn; 857–10th century) was a noted Korean Confucian official, philosopher, and poet of the late Unified Silla period (668-935). He studied for many years in Tang China, passed the Tang imperial examination, and rose to high office there before returning to Silla, where he made ultimately futile attempts to reform the governmental apparatus of a declining Silla state. In his final years, Choe turned more towards Buddhism and became a hermit scholar residing in and around Korea's Haeinsa temple. Choe Chiwon was also known by the literary names Haeun "Sea Cloud" (hɛːun 海雲), or, more commonly, Goun "Lonely Cloud" (koun 孤雲). He is recognized today as the progenitor of the Choe clan of Gyeongju.