Nantang, or the Southern Church built by von Bell in 1680 is the first Catholic church in Beijing. [Photo provided to China Daily]

Seven decades later, when the French Jesuit missionaries including Pierre Jartoux and Guillaume Bonjour-Favre traveled all over what was then the Empire of Qing (1644-1911), working on the most comprehensive and accurate map ever produced of the Middle Kingdom, they may still have had their predecessors in mind.

"They were hard workers before they were 'shepherds', going about their job, be it making calendars or surveying land, with a passion and dedication just as impressive as the skills they harbored," Li says.

"And the way they worked－performing astronomical observations to verify and determine the latitudes and longitudes of various locations－ushered in a new era of cartography in China."

However, the iconoclastic nature of their work, especially in areas that directly challenged the conventional Chinese view of the cosmos, made them targets for attack, often by court officials who felt that their own hold on the emperor's imagination－and on power－was being undermined by these latecomers.