Browning talks about the « common error of historians to undervalue the importance of Spain in the affairs of eighteenth-century Europe ». The period he’s talking about is the post Sun King one, and if France stays a political and cultural beaming centre for the rest of Europe, other processes in Europe create an extension of the centrality and break the concept of Translatio Imperii.
As a consequence, we could say that in one page, Browning talks about different historical characters from different regions and nationalities who are involved in entangled european affairs.