Zhou Zong's birth date is not clearly stated in history — although he was said to be in his 70s at the time of his death during the
Later Zhou invasion against
Southern Tang, which was launched in 956 and ended in 958 in Southern Tang's submission to Later Zhou as a vassal — placing somewhat of a timeframe around the time of his birth. His family was from
Guangling. In his youth late in the
Tang dynasty, there were great disturbances in the region. As a result, he lost his parents, and he was poor. During
Wu (one of the successor states of Tang after Tang fell, which ruled over, inter alia, Zhou's home city of Guangling and had Guangling as its capital), Zhou came to serve under the general
Xu Zhigao, an adoptive son of
Xu Wen, Wu's
regent, as Xu Zhigao's supply officer. Zhou was said to be particularly appropriate in protocols and wording, and served Xu Zhigao well, thus causing Xu Zhigao to greatly favor him. In 933, by which time Xu Zhigao himself had his headquarters at Jinling with his son
Xu Jingtong serving as junior regent at Guangling, Xu Zhigao's chief strategist
Song Qiqiu, who was then a
chancellor, suggested that the Wu capital be moved from Guangling to Jinling. Xu Zhigao thus began palace construction projects at Jinling. However, the project to move the capital was not popular with the people, and Zhou Zong pointed out to Xu Zhigao that if he moved the imperial government from Guangling to Jinling, then, because of Guangling's importance, he would have to move his own headquarters from Jinling to Guangling, effectively doubling the expense of the movement. The project was therefore cancelled. Meanwhile, Xu Zhigao had long considered seizing the Wu throne for himself, but because Yang was known for carefulness, he did not want to take the potentially unpopular action of seizing the throne from him, and therefore wanted to wait until after Yang's reign — a course of action that Song agreed with. However, one day, in Zhou's presence, Xu Zhigao was plucking white facial hair from his face and stating, "The state is secure, but I am getting old." Zhou, who was then serving as the operations officer for Xu Zhigao's headquarters, realized that Xu Zhigao had the intent of taking the throne, and therefore volunteered to head to Guangling to hint to Yang to yield the throne and to inform Song. Xu Zhigao agreed — without first consulting with Song. When Zhou informed this to Yang and Song, Song became jealous of Zhou's doing so, and therefore not only opposed the action but further requested that Zhou be put to death, as an apology to Yang. Xu Zhigao, not wanting to turn against Song's suggestions at this point, while not putting Zhou to death, demoted him out of the headquarters to serve as the deputy military prefect of Chi Prefecture (池州, in modern
Chizhou,
Anhui). However, later, Xu Zhigao's other officers
Li Jianxun and Xu Jie () came to opine the same way as Zhou did, and therefore Xu Zhigao recalled Zhou back to headquarters to again serve as operations officer, while beginning to distance himself from Song. (analogous to the
Shumishi positions of the other states at the time, but not using the character
mi () to observe
naming taboo for Wu's founder
Yang Xingmi). == During Southern Tang ==