Jacobus Clemens non Papa was a Renaissance composer from the Franco-Flemish school. The story goes he gave the nickname "non papa" to himself, so people could differentiate him from the Ypres poet Clemens Papa (Clément de Paepe). The pope, too, (which in Latin is called 'papa') was named Clemens at that time. However, considering that Pope Clement VII died in 1534, before any of Clemens's music was published, and that the confusion with the poet is unlikely in that the surnames were quite distinct, it is likely that the nickname was merely created in jest rather than for practical reasons. Nonetheless, the suffix has remained throughout the ages.
Little is known of his life. He came from one of the seventeen provinces of the current Belgium or the Netherlands (perhaps Zeeland). His first compositions was published in 1536. In 1544 he stayed in Brughes for a year, after which he started a business relationship with the publisher Tielman Susato from Antwerp, who woud publish most of his works until his death. Between 1545 and 1549 he probably was choirmaster to Philippe de Croy, Duke of Aerschot, one of Charles V's greatest generals, where he preceded Nicolas Gombert. According to Antonius Sanderus he was buried at Diksmuide near Ypres in present-day Belgium.
Unlike his contemporaries, Clemens never went to Italy. His style has remained "northern" without Italian influences. He composed a large number of works, among which 15 masses, more than 200 motets and 4 books with in total 159 psalms in Dutch (Souterliedekens). These were published by Tielman Susato in Antwerp.