Wuxi and Lake Tai, by painter Wu Guangzhong. Provided to China Daily

In 1946 Michael and Khoan returned to London and he began his formal study of the language, history and art of China at the School of Oriental and African Studies. He later moved to the United States and completed his PhD in 1952. He then embarked on an academic career, first in the United States, then in Oxford.

Looking back at Sullivan's extraordinary life, Vainker says it was rare for someone of his generation to go to China in his early 20s, and even more unusual to live in the country for six years and to come back with a Chinese wife.

"Usually men of his background and education would get quite a straightforward job in Britain or the US. Sullivan had his own ideas and independent spirit," Vainker says.

Sullivan's life as a teacher, writer, traveler and collector was celebrated with the exhibition Michael Sullivan and Twentieth-Century Chinese Art at the National Art Museum of China in Beijing in 2012, an event to which Vainker contributed.

"The theme was Michael's life as a scholar. We included letters and photographs of his time in China, and photos of him with various artists, and photographs of him throughout his career," Vainker says.

She says preparing for the Beijing exhibition made her better understand Sullivan's vast range of experience in many parts of the world.

"His perspective is never just the perspective of an Englishman. He lived and worked in China, London, the US and Singapore, and traveled to other countries in Southeast Asia. He had a truly international perspective. He was great at making friends and keeping in touch with his friends."

Perhaps it was Sullivan's international perspective that helped him to appreciate Chinese art at a time when it was barely noticed on the international stage. As early as 1959, Sullivan published a groundbreaking book, Chinese Art in the Twentieth Century.

Wang Shiyu contributed to this story.