In the sixteenth century, the Protestant Reformation seriously challenged Catholicism. According to the communis opinio, the Catholic Church as an institution only found an adequate answer towards the end of the century, when it launched a coordinated campaign that implemented the tenets of the Council of Trent (1545–63). In the historiography on the Low Countries, the Fall of Antwerp (1585) is usually designated as the starting point, which coincides with the political separation of the Habsburg Low Countries and the Dutch Republic. This paper challenges this view by investigating Catholic experiments in countering the Reformation in the transitional period from c. 1540 to c. 1580, in both the Southern and Northern Low Countries. Moreover, this paper gives centre stage to the church building, more particularly to the interiors of the cathedrals, collegiate churches and principal parish churches of the larger towns. Our aim is to reconstruct how clergy, court and local elites invested in material culture through a broad range of artistic media. We will pay special attention to the dynamic interplay of objects, their spatial settings in churches and their ritual uses during Habsburg ceremonies.