After briefly showing that, contrary to the received view in analytic circles, Frege's influence on the evolution of Husserl's views on logic and mathematics, as well as on the distinction between sense and referent are either insignificant or, as in the last case, totally inexistent, and that Husserl's account of Leibniz and Bolzano's influence in Logische Untersuchungen is correct, we turn to Riemann, whose influence is certainly non-negligible. Husserl's conception of mathematics as a theory of manifolds (or structures) is a generalization of Riemann's notion of manifold – in fact, a sort of bridge between Riemann and the Bourbaki group. Moreover, Husserl's conception – since 1892 – of physical geometry as empirical is also strongly influenced by Riemann