In this Thesis I investigate how Fano manifolds equipped with a Kahler- Einstein metric can degenerate as metric spaces (in the Gromov-Hausdorff topology) and some of the relations of this question with Algebraic Geometry. A central topic in the Thesis is the study of the deformation theory for singular Kahler-Einstein metrics. In particular, it is shown that Kahler- Einstein Fano varieties of dimension two (Del Pezzo surfaces) with only nodes as singularities and discrete automorphism group, admit (partial) smoothings which also carry (orbifold) Kahler-Einstein metrics. The above result is then used to study the metric compactification in the Gromov- Hausdorff topology of the space of Kahler-Einstein Del Pezzo surfaces. In the case of cubi...