Cao Hongda was born in 882, during the reign of
Emperor Xizong of Tang. His father Cao Gui (曹圭) was a general under
Qian Liu, who would eventually control the region (modern
Zhejiang) that became the territory of
Wuyue. Cao Hongda was born at Linping (臨平, in modern
Hangzhou,
Zhejiang). After he grew older, Cao Gui wanted to train him physically, so Cao Gui had him eat with servants and not be given warm clothing even when it was in the winter. Cao Gui also had him lift bricks daily. After Cao Hongda grew yet older, he became a guard at the headquarters for one of the circuits Qian controlled, Zhendong Circuit (鎮東, headquartered in modern
Shaoxing,
Zhejiang). At that time, his father Cao Gui served as the prefect of Su Prefecture (蘇州, in modern
Suzhou,
Jiangsu), and wanted to enter into a marital alliance with a fellow general under Qian, Chen Xun (陳詢) the prefect of Mu Prefecture (睦州, in modern Hangzhou) — by having Cao Hongda marry one of Chen's daughters. He thus sent Cao Hongda on a mission to Mu, intending to have him marry Chen's daughter there. However, a fortuneteller informed Cao Hongda and/or Cao Gui, "The Chens are not appropriate for your marital relationship. You should marry with another family to bring glory and honor on you." When he went through the Qiantang (錢塘, in modern Hangzhou), the capital of Qian's main circuit, Zhenhai Circuit (鎮海), Qian was impressed by Cao Hongda's appearance, and therefore gave him a younger sister in marriage. Cao Hongda thereafter successively served as the prefect of Tai Prefecture (台州, in modern
Taizhou,
Zhejiang), then of Chu Prefecture (處州, in modern
Lishui,
Zhejiang). == Service under Qian Yuanguan ==