The most important traditional topics of empirical theory of democracy have been deeply reshaped by the phenomenon of the diffusion of democracies in the world during at least the last 30 years. More precisely, the definition of democracy is reconsidered under the new light shed by that phenomenon; the issue of hybrid regimes is addressed with all its problems of empirical intractability; the issue of the emergence of a theory, a quasi theory or at least a good theoretical framework about democratisation processes is discussed; and finally a contested issue such as that of the empirical assessment of democratic quality is introduced.