We propose an elegant theory of flavour based on A 4 × Z 5 family symmetry with Pati-Salam unification which provides an excellent description of quark and lepton masses, mixing and CP violation. The A 4 symmetry unifies the left-handed families and its vacuum alignment determines the columns of Yukawa matrices. The Z 5 symmetry distinguishes the right-handed families and its breaking controls CP violation in both the quark and lepton sectors. The Pati-Salam symmetry relates the quark and lepton Yukawa matrices, with Y u = Y ν and Y d ~ Y e . Using the see-saw mechanism with very hierarchical right-handed neutrinos and CSD4 vacuum alignment, the model predicts the entire PMNS mixing matrix and gives a Cabibbo angle θ C ≈ 1/4. In particular, for a discrete choice of Z 5 phases, it predicts maximal atmospheric mixing, θ 23 = 45° ± 0.5° and leptonic CP violating phase δ l = 260° ± 5°. The reactor angle prediction is θ 13 = 9° ± 0.5°, while the solar angle is 34° ≳ θ 12 ≳ 31°, for a lightest neutrino mass in the range 0 ≲ m 1 ≲ 0.5 meV, corresponding to a normal neutrino mass hierarchy and a very small rate for neutrinoless double beta decay.