Preparing a handbook on diplomacy nowadays reflects a major challenge that was not present during Satow’s times, and which lets us say a great deal more about diplomacy than Satow could. Specifically, a handbook today encounters and benefits from the development over the last 100 years of the academic discipline of International Relations and within it the rich and expanding field of Diplomatic Studies. It must therefore refer to and engage this literature – the accumulated body of knowledge on diplomacy. Indeed, a practical guide that disregards such theoretical developments – that is, the more or less systematic thinking aimed at understanding and explaining diplomatic practice – will be broadly unreflective and have little practical utility as to what works as well as how, where and when it works, or doesn’t work. It is useful to remember that practice moves on in ways that practitioners sometimes are the first to understand and recognize, yet also sometimes dogmatically resist acknowledging for a variety of reasons. At the same time, theory is sometimes pioneering in analyzing trends or re-conceptualizing practice, yet sometimes only belatedly catches up on what practitioners realized and routinely practiced for some time.