Olaus Petri was a Swedish clergyman, writer, and judge who played a central role in bringing the Protestant Reformation to Sweden. Born in Örebro in 1493, he studied theology in Uppsala, Leipzig, and Wittenberg, where he was influenced by Martin Luther and Philipp Melanchthon. Following the Swedish War of Liberation, he served as a chancellor and town secretary in Stockholm. He is most recognized for his extensive literary contributions, including translating the New Testament and the Bible into the Swedish language, which helped establish the vernacular in religious practice.