  We present a detailed discussion of the asymptotic symmetries of Anti-de
Sitter space in two dimensions and their relationship with the conformal group
in one dimension. We use this relationship to give a microscopical derivation
of the entropy of 2d black holes that have asymptotically Anti-de Sitter
behaviour. The implications of our results for the conjectured AdS_2/CFT_1
duality are also discussed.
