This article examines Comenius's extensive correspondence network of which 560 sent and received letters survive. The first aim is to look closer at the letters from the early period of Comenius's life with special regard to his position within the communication network of the Unity of Brethren and to his fundraising activities. Second, it shows how Comenius's correspondence network expanded beyond the structures of the Unity and became a part of the international network of learned correspondence. It also discusses how this network was used in favor of the Unity and how it provided a new type of patronage for the Brethren. It demonstrates that Comenius's didactic and pansophic agenda was often in conflict with his ecclesiastical duties and sometimes with the efforts of his correspondence partners. Finally, the article focuses on two examples of personal correspondence networks of two important recipients of Comenius's letters: Petr Figulus and Mikuláš Drabík. Both of them were ministers of the Unity, both were close to Comenius, and their networks were built with his help but with very different purposes.