Vajirananavarorasa (also spelled Wachirayan, Watchirayanawarorot, correct Pali spelling: Vajirañāṇavarorasa, วชิรญาณวโรรส, full title Somdet Phramahasamanachao Kromphraya Vajirananavarorasa สมเด็จพระมหาสมณเจ้ากรมพระยาวชิรญาณวโรรส ) (12 April 1860, Bangkok, Thailand - 2 August 1921, Bangkok, Thailand) was the tenth Supreme Patriarch of Thailand from 1910 to 1921. He helped to institutionalize Thai Buddhism. Destined to become "the leading intellectual of his generation in Siam", in the words of the Thai historian David K. Wyatt (cited in Reynolds 1979:xiii), his royal name was Prince Manuṣyanāgamānob (พระองค์เจ้ามนุษยนาคมานพ) ('he who is a nāga among men'). Vajirañāṇavarorasa is the name he received on a gold nameplate together with the Krommamuen rank on 16 March 1882. Vajirañana was the 47th child of King Mongkut. He was born in the Grand Palace as the fourth child of Phae, one of King Mongkut's concubines. She died after giving birth to her fifth child, a daughter, when he was one year old. He was then fostered by a maternal relative, Princess Varaseṭhasutā or "Putrī", a daughter of King Rama III, and her mother, a royal concubine named Samaśakti or "Ueng". In the palace, he was taught the Siamese alphabet by a woman, Nok Panakngan. The nobleman Phraya Pariyatidharrmadhātā or "Piam" (then called Luang Rājābhirama), deputy head of the Royal Pundits Department, came to the Palace to teach the young Vajirañana and other princes the Khmer script used to inscribe religious texts in Pāli. With a teacher who was official at the Outer Court, Vajirañana studied Padamālā (Pāli grammar), the Dhammapada commentary, and other texts until 1868. When his elder brother, Prince Brahmavarānurakṣa, ordained as a novice, Vajirañana was allowed to live with him in Wat Pavaraniveśa for some while. There he occasionally studied Pāli scripture with Phra Pariyatidharrmadhātā ("Chang", then Luang Śrīvaravohāra), one of the four section chiefs in the Royal Pundits Department, who taught monks and novices at the monastery.