We know he was an Irishman, and a Catholic, who was the personal delegate of the Qing Government to Leo Xlll in the Vatican.
At that time France claimed to be the protector of all Catholic missionaries in China. Though anti-Catholic at home, the French government believed ‘anti-clericalism is not for export,’ wishing to extend its international influence through its missionaries, especially in China.
Li Hong-zhang, the Chinese foreign minister, saw the need to by-pass the French and open direct access to the Pope in Rome. In 1885 he consulted his confident, Robert Hart, the Chinese Customs Inspector General and Protestant Irishman, who recommend John Anthony Dunn to carry the message. Dunn worked for Hart in the Tianjin customs and was a Catholic.
The Pope welcomed the proposal to send a Papal Delegate to Beijing and receive a Chinese Minister at the Holy See. However the French strongly objected as they saw it as reducing their influence. Nevertheless, discussions between the Vatican and China went ahead and were nearing final agreement when the Pope gave in to the pressure from French Catholics, fearful of retaliation from their own government. The project was abandoned for the time being.
But who was John George Dunn who conveyed the messages between Beijing and Rome? His role was drawn to my attention by Dr Paul Dang but not even Google could provide me with further detail.