The diffraction of X-rays by crystals was discovered more than sixty years ago. Since then, crystallography has established itself and created an ever-widening sphere of influence in science. Crystal structure resolution has had an increasing impact in many fields, such as physics, chemistry, biology, materials science, metallurgy, mineralogy, and geology. So-called ‘direct methods’ for solving crystal structures have developed rapidly in recent years. These methods, based on mathematical relationships between the phases of X-ray diffracted beams, are particularly suitable for automation, and there are now computer programmes that can solve structures with seventy, or even more, equal atoms in the asymmetric unit. The aim of this institute of advanced studies will be to present direct methods starting from first principles and arriving at the latest developments in the subject. Formal lectures will be complemented by discussions and practical classes, and instructors will include most of the internationally recognised authorities in the field.