Project B04 investigates register variation in the Early Modern context of the Reformation, when religious and other writing and printing expanded dramatically. We will model register emergence and transfer, focusing on the intraindividual register knowledge of two prolific individuals central to the development of German and Lithuanian respectively: Martin Luther (1483–1546) and Johannes Bretke (1536–1602). We will analyze linguistic, particularly grammatical and lexical phenomena in varied historical registers. Methodologically, the project combines a bottom-up approach based on individual linguistic phenomena with a top-down approach clustering parameters to arrive at a register classification.