Zhang Chonghua - Era Name?

Era Name?

Most historical sources indicate that Zhang Chonghua, like his grandfather Zhang Shi (張寔), his granduncle Zhang Mao, and his father Zhang Jun, continued to use Emperor Min of Jin's era name Jianxing (both to show continued allegiance to Jin and to distance himself from Emperor Yuan of Jin and his line) but some sources indicate that he changed era name to Yongle (永樂 yǒng lè 346-353). A current theory is that his era name was used internally while the Jianxing era name was used when communicating with other states.