As Cicero once said, ‘A letter doesn’t blush’. Letters can be impersonal, but also very intimate. What has once been committed to paper for a single recipient, may offer later readers insight into the biography of the sender and into the cultural climate of his time. These are good reasons to keep letters, even after the addressee is deceased. No-one knows exactly how many letters are kept in the Special Collections, but the number is huge: a recent tally estimates over 500,000 items, dating from the fifteenth century to the present. It makes this collection of letters one of the largest in the Netherlands, if not the largest.