So the job Robert Walpole performed from 1721 and Boris Johnson from 2019 had much in common. But the country they headed was vastly different. In this chapter, we explore some of the more momentous technological, political, cultural, and social changes that occurred over the 300 years. Only by appreciating these factors, which have been perhaps under-considered in the literature on the office to date, can a rounded appreciation of it be achieved. The sheer pace and extent of change makes the survival of the office of prime minister over 300 years, and the adaptability of the individuals involved, even more remarkable.