 In the Tang Dynasty period 9th century, An was also sometimes used as the name for the region of Sogdia; previously, Sogdians had exclusively used the surname of Kang (康).The addition was due to the existence of two Sogdian kingdoms, identified as An and Kangju; the state of An was accordingly named due to its occupation by the Arsacids.It is considered one of the "Nine Sogdian Surnames."