This copy of Lucretius' poem De rerum natura (On the nature of things), edited by Denis Lambin and printed in Paris in 1563, belonged to the French writer Michel de Montaigne (1533-1592) and is covered with his notes and annotations. Discovered as recently as 1989, it came to Cambridge University Library in 2008 as part of the library of the Montaigne scholar and financier Gilbert de Botton (1935-2000), a remarkable collection of books connected with Montaigne, his life and times, and his library, including ten of Montaigne's personal copies. The influence of Lucretius on Montaigne had long been recognised. Montaigne quotes him extensively in his Essais, particularly in the chapters 'To philosophise is to learn how to die' and 'An apology for Raymond Sebond'. The survival of this volume allows us a remarkable insight into the way that Montaigne read and understood Lucretius.