  The formation of early-type dwarf (dE) galaxies, the most numerous objects in
clusters, is believed to be closely connected to the physical processes that
drive galaxy cluster evolution, like galaxy harassment and ram-pressure
stripping. However, the actual significance of each mechanism for building the
observed cluster dE population is yet unknown. Several distinct dE subclasses
were identified, which show significant differences in their shape, stellar
content, and distribution within the cluster. Does this diversity imply that
dEs originate from various formation channels? Does "cosmological" formation
play a role as well? I try to touch on these questions in this brief overview
of dEs in galaxy clusters.
