Originally from Guangling commandery (covering parts of present-day Jiangsu), Zhang Hong and Zhang Zhao were known as the "Two Zhangs" and they were "recruited" together by Sun Jian. He was a close friend of the Sun family, and when Sun Jian was involved in his campaigns, Zhang Hong served him as a privy advisor. In the days of Sun Ce, Zhang Hong was often responsible for writing official memorials and essays to Emperor Xian and Cao Cao. After Sun Ce's death, he was sent to serve Cao Cao, and then was later sent by Cao Cao to monitor Sun Quan's activities. Zhang Hong, however, remained loyal to Sun Quan, and on his deathbed, petitioned Sun Quan to develop the city of Moling (present-day Nanjing, Jiangsu), which ultimately became the capital of Wu.