  We show that a system with competing interactions on different length scales,
as relevant for the formation of stripes in doped Mott insulators, undergoes a
self-generated glass transition which is caused by the frustrated nature of the
interactions and not related to the presence of quenched disorder. An
exponentially large number of metastable configurations is found, leading to a
slow, landscape dominated long time relaxation and a break up of the system
into a disordered inhomogeneous state.
