  This paper studies the existence and asymptotic behavior of global weak
solutions for a thin film equation with insoluble surfactant under the
influence of gravitational, capillary and van der Waals forces. We prove the
existence of global weak solutions for \emph{medium sized} initial data in
\emph{large function spaces}. Moreover, exponential decay towards the flat
equilibrium state is established, where an estimate on the decay rate can be
computed explicitly.
