The thesis provides a detailed historical account of the Sino-Belgian Catholic network and argues that by promoting mutual communication it contributed to building up a sense of solidarity, inspiring people to see shared concerns beyond pre-set borders, in particular in the case of The Blue Lotus. The question of whether the Roman Catholic Church in China should be westernized or Sinicized has hung over its actions in modern China. In the context of western power superiority, a strengthened hierarchy and Roman orthodoxy, the Catholic mission promoted westernization of the church and converts in China. But this approach caused a social backlash, as seen in the numerous missionary incidents. Imposed westernization has also been criticised by scholars of mission history, who argue that the Church should have been Sinicized to suit the environment. In contrast with this dualistic narrative, this study shows that in the early twentieth century the Sino-Belgian Catholic network advocated the compatibility of different cultures, which was vividly demonstrated in the making of The Blue Lotus episode of the popular Belgian comic, The Adventures of Tintin, serialized on the newspaper Le Petit Vingtième from 1934-35. The Blue Lotus was set in China and presented the friendship between Tintin and his Chinese friend Tchang. The comic was the result of collaboration between Hergé, its creator, and Zhang Chongren, a Chinese art student in Brussels. Their meeting was the result of the initiatives of Chinese and Belgian Catholics including Ma Xiangbo, Lu Zhengxiang and Vincent Lebbe. From around the turn of the twentieth century, this group of Catholics had focused on deepening mutual communication, so as to reduce misunderstandings and the attendant tensions. Faced with political and institutional obstacles, such as the lack of an official China-Vatican relationship and the presence of the French Protectorate in China, the network sought to provide facilities and create an environment on the ground where mutual dialogue became possible, such as the Catholic project for Chinese students based in Belgium. When the Mukden Incident broke out in 1931, this Catholic network sought to generate support to China in Belgian media, which led to the creation of The Blue Lotus. In the 1930s, the comic’s message to readers of solidarity with China meant opposition to Japanese aggression during the Sino-Japanese conflict. In later periods, the Tintin-Tchang friendship in the story, and the syncretic creations coming out the Hergé-Zhang encounter, such as the “clear line” artistic style of Hergé, inspires readers of Tintin to realize the meaning of mutual understanding and cross-cultural dialogue.