Erasmus’s Latin and Greek New Testament of 1516 was accompanied by annotations intended to be brief but which were already challenging and often discursuve. This edition gives them with all their variants. The years 1519, 1523, 1527 and 1535 saw these notes grow and grow in number, size and importance. Some treat just those minutiae which led Aquinas, say, into error or folly when he ignored or neglected them; others form ever-expanding essays spreading over several pages and bringing Erasmus into the centre of controversy. The annotations are edited and dated in this work. They form an important companion to Erasmus’s letters as a major source of the knowledge of the nuances and development of his thought and scholarship.