This is the second edition of my book Galaxy Formation. Many people liked the rst edition which appeared in 1998, just before the explosion of magni cent new data which have completely changed the face of astrophysical cosmology. Many of the agonies which had to be gone through in the rst edition have disappeared and, to many people¿s amazement, including mine, there is now a concordance model for cosmology, the cosmologist¿s equivalent of the particle physicist¿s standard model. Just like the standard model, however, the concordance model creates as many problems as it solves. This is not a cause for concern, but rather one for celebration because we are now able to ask much better and deeper questions than in the past. These questions indicate clearly the need for physics and astrophysics ¿Beyond the Concordance Model¿. Theobjectofthisneweditionistobringthisamazingstoryup-to-date,verymuch inthespiritofthe rstedition.Torecapitulatesomeofthepointsmadeintheprevious prefaceabouttheoriginofthebook,IwasaskedbySpringer-Verlagtoexpandtheset of lecture notes that I prepared in 1988 for the First Astrophysics School organised by the European Astrophysics Doctoral Network into a full-length book. The set of notes was entitled Galaxy Formation and was published as a chapter of the volume Evolution of Galaxies: Astronomical Observations (eds. I. Appenzeller, H.J. Habing andP.Lena,pages1to93,Springer-VerlagBerlin,Heidelberg,1989).Inthatchapter, Iattemptedtobridgethegapbetweenelementarycosmologyandthetechnicalpapers appearing in the literature which can seem quite daunting on rst encounter. The objective was to present the physical ideas and key results as clearly as possible as an introduction and guide to the technical literature.