While Ji Chang governed Western Qi his eldest son Bo Yikao was still at Chaoge, so Ji Fa managed the grain, the taxes and the correspondence of the lords with his father in the city. After Bo Yikao’s death, Ji Fa became the heir to the title of Earl of the West.
When Ji Chang came home from Youli and led Western Qi against Mixu and Chong, Ji Fa went with the army to watch and then took charge of the government in the capital. Gravely ill, Ji Chang called Ji Fa, Jiang Ziya and his other sons to his bedside, told Ji Fa to serve Jiang Shang as a father and not to press east too quickly, and put the ancestral temple, the altars and the officials of Western Qi into his hands.
When the funeral was over, Ji Fa took the seat before the coffin, honoured Jiang Ziya as Shangfu, and kept his father’s ministers and military order. Only when the passes of Western Qi were secure did he take up the campaign against Shang his father had not lived to finish, cross at Mengjin and march on Chaoge.