Amoghavajra (Bukongjin’gang不空金剛; 704/5-774) was a historically significant Buddhist monk who operated in China during the Tang dynasty (618–907). He was a prolific translator and is widely regarded as the founder of an Esoteric or Tantric Buddhist tradition in East Asia. Arriving in China at a young age, Amoghavajra became a monk and practiced under Vajrabodhi (Jin’gangzhi金剛智; 671–741). Following his master’s death, Amoghavajra undertook an ocean voyage to Sri Lanka and southern India. He returned to Tang China in 746/747 with a collection of newly acquired Buddhist texts and training in ritual practices. He was the recipient of patronage and support from members of the ruling elite in Tang China, including a succession of three emperors—Xuanzong 玄宗 (r. 713–756), Suzong 肅宗 (r. 756–762), and Daizong 代宗 (r. 762–779). Amoghavajra served the Tang government with his ritual services and was appointed a minister in the central government bureau charged with overseeing official ritual services for the Tang state. With this support and influence, Amoghavajra translated a vast collection of Buddhist scriptures and authored numerous commentaries, ritual manuals, and compendia, and he effectively established a teaching of Buddhism in China that is generally referred to as “Esoteric Buddhism.” This teaching of Buddhism was subsequently transmitted by Kūkai 空海 (774–835) to Japan, where it became established as the Japanese Shingon school. In Chinese and Japanese Buddhist histories, Amoghavajra is regarded as a patriarch of Tang dynasty Esoteric Buddhism and Japanese Shingon.