Kraków at that time was fierce, and Vietor got into conflicts with other printers over printing rights several times. In 1527, Vietor managed to gain a printing privilege for calendars, an important income source, for ten years. After that, the privilege should fall to fellow printer Matthias Scharffenberg. When Vietor printed a calendar in 1538 all the same and Markus Scharffenberg distributed it, Matthias Scharffenberg, a relative of Marcus, took them to court, and won. In 1536 Vietor got into conflict with the Catholic church. Vietor was a humanist, open to new ideas, and not afraid to publish works about such novelties, including new religious ideas, although he himself was never openly Protestant. He was accused and arrested for having imported and distributed "heretical" books with images that "offended" the Church. The precise history of this process is not known; in any case Vietor came out of it unscathed. It appears that he had had to reaffirm his Catholic faith before the bishop, though. Vietor's death date is not known precisely, but it must have been between September 25, 1546 (last mention in the acts of the vicariate of Kraków) and March 21, 1547, when his wife is mentioned as a widow. Vietor was married twice. From his first marriage to Apolonia, he had one son (Florian Vietor, died 1532). After her death, he married again; with his second wife Barbara, he had five daughters, four of which died in infancy. After Vietor's death, Barbara married his apprentice Łazarz Andrysowicz (Lazarus Andrea), who continued the business and who would become famous in his own right. Their son Jan Łazarzowicz Januszowsky (Johannes Lazarides Janussovius) would become known as a printer and writer, too. Works Vietor was a most prolific printer: the output of his print shop in Kraków from 1518 to 1547 numbers more than 600 prints. Most of these prints were in Latin, but Vietor was also the first printer to print regularly in Polish, which accounts for 10-15% of his output. He also printed a number of multilingual works (Latin, Polish, and German). Vietor printed parts of the Bible in Polish, but also humanist works, for instance of Erasmus of Rotterdam, and a number of Polish grammars and dictionaries. Printing in Polish instead of in Latin made these works readily accessible to a much larger sector of the population. His prints were of high quality; he possessed very good