The religious world of late medieval and early modern Central Europe is complicated, convoluted and, above, all entangled. But despite the real and tangible connections that linked the various polities of this region together, scholars have tended to explore this landscape along anachronistic divisions defined narrowly by language and nation. This article, by contrast, examines connections that developed between the Bohemian and Austrian lands. It begins in the mid-fourteenth century by exploring rivalling efforts of Emperor Charles IV in Prague and his son-in-law, Duke Rudolf IV of Austria, to build the institutional foundations upon which critical ecclesiastical changes occurred in the following three centuries. The chapter traces parallel reform programmes in the fifteenth century that had very different outcomes. While Hussitism left Bohemia isolated, the efforts of Nicholas of Cusa and others helped to integrate the Austrian lands into the broader ecclesiastical culture of the West. The sixteenth century brought an Erasmian humanism to both regions as well as more radical expressions of reform. Protestantism reached its high point here in the late sixteenth century only to collapse dramatically a few decades later with the great crisis of the Thirty Years’ War. The chapter concludes with a comparison of the exiles who left this region after the Catholic victory.