Martin Luther OSA (/ˈluːθər/; German: [ˈmaʁtiːn ˈlʊtɐ]; 10 November 1483 – 18 February 1546) was a German priest, theologian, author, hymnwriter, and professor. A former Augustinian friar, he is best known as the seminal figure in the Protestant Reformation and the namesake of Lutheranism.