大秦景教流行中国碑
Alopen (, Middle Chinese: "AlapuənX"); also "Aleben", "Aluoben", "Olopen," "Olopan," or "Olopuen") is the first recorded Christian missionary to have reached China, during the Tang dynasty. He was a missionary from the Church of the East (also known as the "Nestorian Church"), and probably a Syriac speaker from the Sasanian Empire or from Byzantine Syria. He is known exclusively from the Nestorian Stele, which describes his arrival in the Tang capital of Chang'an in 635 and his acceptance by Emperor Taizong of Tang. His is the earliest known name that can be attached to the history of the Church of the East in China.