Hobbes said that the ruler was there for the sake of the people, not vice-versa.
I haven't got the text handy, so I can't give a chapter and paragraph reference, but it's in 'Leviathan'.
He was not the first to say something similar. Plato said it in 'The Republic' and it was a commonplace of mediaeval Christian thought.
Hobbes however discusses the basis of political authority and the implied contract between ruler and ruled in a depth and from a viewpoint totally new in his day.
