The clan was founded by Jang Sun-ryong [ko], an Arab-Uiguric Muslim civil servant who served in the Goryeo court.
[citation needed] Jang Sun-ryong (장순룡, 張舜龍; 1255-1297) was originally of Uyghur descent, and was the son of Jang Baek-chang (장백창, 張伯昌; 1230-1254), who held the official title of Pildo-chi (필도치, 必闍赤) during the reign of the Yuan Dynasty.
Lee Hyeon (이현, 李玄), the founder of the Imcheon Lee clan (임천 이씨), and Seol Son (설손, 偰遜), the founder of the Gyeongju Seol clan (경주 설씨), are said to be Uyghurs and from the Seolian River, like Jang Baek-chang.
[1][2] He later became a naturalized citizen of Goryeo; becoming Cheomuichamri (첨의참리, 僉議參理) and Munhachanseongsa (문하찬성사, 門下贊成事).
The Deoksu Jang clan produced 14 people who passed the civil service exam, 1 Queen, and 2 Royal consorts during the Joseon Dynasty.