While Columbus likely believed until his death that he had found the sea route to Asia, Amerigo Vespucci was convinced that the newly discovered coastal landscapes must be a separate continent. In his travel reports Mundus Novus and Four Voyages, which are preserved in epistolary form and were never challenged during his lifetime, he repeatedly emphasizes this. This changed when the cartographer Martin Waldseemüller, together with the humanist Matthias Ringmann, published a world map in 1507 that included the new continent for the first time and named it "America.".