The University of Cambridge can point to a long roster of distinguished scientists and mathematicians who have been associated with its history over the past 400 years, since the ‘scientific revolution’ of the seventeenth century. Their names include three of the greatest luminaries in the entire history of science: Isaac Newton, Charles Darwin, and James Clerk Maxwell. The link between the Cambridge present and the magnitude of past achievement is highlighted by the names given to institutions and buildings in the University: Darwin College, the Newton Institute, Harvey Court. This sense of continuity, that the work of the present age is linked to the traditions of the founding fathers, has prompted this collection of essays on Cambridge scientists, intended to interest a broad non-specialist readership within and beyond the University. But to the historian such associations, though beguiling, are problematic, suggesting sentiment or constructed ‘heritage’ rather than historical reality. Can figures of the early modern period – Isaac Newton, William Gilbert, William Harvey – be properly described as ‘scientists’? The term, with its resonances of professional specialisation, was only introduced (by another Cambridge notable, William Whewell) in 1834. Does Cambridge ‘science’ have a 400-year history, or is it a product of the professionalisation of science, of teaching and research, since 1850 and especially since 1900? Is there indeed a specifically Cantabrigian scientific culture? The three major scientific figures associated with the University illustrate some of the problems in defining Cambridge science.