The present work documents landmarks in the evolution of the foreign relations of leading states, from the start of the modern era until the mid-twentieth century. It is meant as a contribution to the professionalisation of the practice of leadership at the global level. For the responsibilities, dangers and opportunities of global leadership merit much more explicit (yet also well informed) treatment than they have received so far. And a most important need is for a memory (or genealogy) of the problems experienced by those who dared to launch great global initiatives, and of the solutions that did (or did not) serve them well.