A photo captured this historic moment－Hart onboard a ship surrounded by customs staff in full dress uniform.

O'Neill chose this photo for the book cover.

In the latest book, O'Neill tries to strike a balance by including the comments of Chinese historian Wang Hongbin.

In his biography of Hart published in 2010, Wang wrote: "Hart was the most important invader representing British interests, who put the interests of that country above those of China."

O'Neill includes this in his preface telling readers: "We leave you to make your own judgement."

Contact the writer at xingyi@chinadaily.com.cn

Chen Mengwei contributed to this story.