Chang, Zheng, Zhang, Chong, and Teoh are all of the same Chinese family name "long bow". 1. 古國名。 2. 原指春秋戰國時鄭國的民間音樂，後與所謂雅樂對舉，指與雅樂相背的「淫邪之音」。 3. 鄭重；殷勤。 4. 姓。
The following are Chang's origin, some genealogical records and migration path is according to clan genealogical records.
Yong Tong, third wife of Huang Ti (Yellow Empror), bore Huang Ti his fifth son. HT's fifth son invented powerful long bow and was made the "bow" official and was given the Family name "Long Bow" or Chang; He then moved to ShanSi, Tai Yuan Fu and became the ancestor of the Chang's clan. His full name is Chang Hui(shine).
After some period of time, several powerful Chang clans appeared including the one that lived in Hsu Zhou, Ching (Clear) He (River). I believe there were 12-14 Chang clans recorded in some historical records in ancient time. Today many of the oversea Changs are from the Ching He clan lineage. That is where all the plaques in the Chinese houses are for, to indicate their clan origin. CHANG Character