Hilbert obtained his doctorate in 1885, with a dissertation, written under Ferdinand von Lindemann, titled *ber invariante Eigenschaften spezieller bin*rer Formen, insbesondere der Kugelfunktionen (``On the invariant properties of special binary forms, in particular the spherical harmonic functions''). Hilbert remained at the University of K*nigsberg as a Privatdozent (senior lecturer) from 1886 to 1895. In 1895, as a result of intervention on his behalf by Felix Klein, he obtained the position of Professor of Mathematics at the University of G*ttingen.
Hilbert
Felix Klein