While little is known about his early life, a Flemish origin along with a French upbringing has been suggested from variations on the spelling of his name, and he may originally have been from the vicinity of Liège or Namur, in present-day Belgium. He moved to Italy as a young man, and was present in Florence by the late 1520s, therefore having an opportunity to meet or work with Philippe Verdelot, who wrote the earliest named madrigals. In or immediately before 1538 he moved to Rome where he obtained an appointment with the papal choir at St. Peter's Basilica; many composers from the Netherlands served as Singers there throughout this era, and it is even possible that he went to Rome before coming to Florence. Still in Rome, in January 1539, he probably was made a member of the Julian Chapel (the records give his name as "Jacobus flandrus", suggesting a Flemish origin, but it cannot be known with certainty if this record referred to Arcadelt). After some months there he became a member of the Sistine Chapel, where he was appointed "magister puerorum." The same year saw the publication of no less than four books of his madrigals. The first of these collections, Il primo libro di madrigali, went through 45 editions, becoming the most widely reprinted collection of madrigals of the time.