The Zhang tribe had a long-standing conflict with the Gan Jin tribe, with their disputes tracing back to 0 ASC. Tribe lore held that the clan's founder, Wei Jin, found the Gan Jin leader, Jin Wei, collapsed from exhaustion, and offered his assistance. Jin Wei told him to take the sacred crystal orb back to his tribe. However, when he arrived, Wei Jin was accused of stealing the orb and imprisoned for twenty years as punishment for the alleged crime.
Historically, the Zhang had been a society of hunters and outdoorsmen, though by 100 ASC, the tribe had taken more interest in a variety of industries.
During the Hundred Year War, the Fire Nation attacked the tribe, forcing them to flee their homeland. The Zhang became refugees fleeing to the capital city of Ba Sing Se. Aang escorted the Zhang and the Gan Jin tribes across the Great Divide and was able to bring peace between the two clans through a rather elaborate lie. He claimed that Wei Jin and Jin Wei were twins, and Wei Jin had not been imprisoned for twenty years, but was instead placed in the penalty box for two minutes for stepping out of bounds in a game called Redemption. In addition, he stated that the sacred orb was simply a ball, and the Great Eastern and Western Gates involved in the ritual were just the goal posts in the game.
The Zhang adorned themselves in brown rags and fur pelts, and dismissed cleanliness. They were generally uncivilized, and were extremely messy and unkempt, yet relatively more practical, pragmatic and flexible about their way of living. This was due in part to their history as a society of hunters and outdoorsmen.