This course is intended to provide an overview of cryptography. We will take a tour through history, looking at the earliest ciphers, through the secret-key methods that took over, through to current methods such as public-key methods, and also look at the future possibilities as the next step. The course consists of a series of short lectures on slides - many have supplementary notes and questions to attempt, with fully-worked solutions provided. The course is intended to be informative but also enjoyable - my aim is that you learn something about cryptography, but also enjoy it and are motivated to find out more!