In the early 1950s, when the newly founded People's Republic of China just began to recover from social upheaval and was still a poor country, a costly cultural mission was made a priority.

The endeavor was to rescue many national treasures from getting lost overseas.

Now, an exhibition at the National Library of China is displaying letters, notes and telegraph messages exchanged between Zheng Zhenduo, the first director of the National Cultural Heritage Administration after New China's founding in 1949, and a group of unsung heroes in Hong Kong.

A succession of wars resulted in cultural relics going from the mainland to Hong Kong, which was ruled by the United Kingdom at the time, attracting the attention of foreign collectors.

In 1951, following then-premier Zhou Enlai's guidance, Mid-Autumn Festival and Letter to Boyuan, dating back to the Eastern Jin Dynasty (317-420), among the most important paper-based works in Chinese fine art history, were bought from a private collector. The two calligraphy pieces cost 500,000 HK dollars (then $87,500), roughly 0.2 percent of China's total foreign exchange reserve at that time. The artworks returned to the Forbidden City－now the Palace Museum－in Beijing, where they were previously kept by Qing Dynasty (1644-1911) emperors.