In 1958 the future nobel-prize winning physicist Philip W. Anderson argued that electrons moving in a crystal with randomimpurities tend to localise, as opposed to the usual conduction observed in pure crystals. 60 years later and this groundbreaking idea is still at the bleeding edge of semiconductor and ultra-cold matter physics. Mathematically, the so-called Anderson localisation phenomenon is concerned with spectral properties of randomSchrodinger operators. In this course, we will explore how probability theory has shed light on some of the mysteries in this area, and we aim to convey to the audience that there are a rich range of beautiful open problems that remain.