Flavour symmetry for the light generations

The quark sector of the Standard Model exhibits an approximate U(2)^3 flavour symmetry under which the first two generations transform as doublets and the third generation as singlets. This symmetry, broken in specific directions dictated by minimality, can explain the success of the CKM picture of flavour mixing and CP violation while allowing for observable deviations from it, as expected in most models of electroweak symmetry breaking. In a general effective field theory framework, I will discuss the symmetry and its breaking, its relation to Minimal Flavour Violation and the consequences for flavour physics in the quark and lepton sectors. Finally, I will discuss its realization in two concrete models: natural supersymmetry with split families and generic composite Higgs models.