  We prove a version of Quillen's stratification theorem in equivariant
homotopy theory for a finite group $G$, generalizing the classical theorem in
two directions. Firstly, we work with arbitrary commutative equivariant ring
spectra as coefficients, and secondly, we categorify it to a result about
equivariant modules. Our general stratification theorem is formulated in the
language of equivariant tensor-triangular geometry, which we show to be tightly
controlled by the non-equivariant tensor-triangular geometry of the geometric
fixed points.
  We then apply our methods to the case of Borel-equivariant Lubin--Tate
$E$-theory $\underline{E_n}$, for any finite height $n$ and any finite group
$G$, where we obtain a sharper theorem in the form of cohomological
stratification. In particular, this provides a computation of the Balmer
spectrum as well as a cohomological parametrization of all localizing
$\otimes$-ideals of the category of equivariant modules over $\underline{E_n}$,
thereby establishing a finite height analogue of the work of Benson, Iyengar,
and Krause in modular representation theory.
