A review is presented of interpretations made to date of the Irish Var
iscides, and the various models of Late Palaeozoic crustal evolution.
An examination is then made of the factors controlling Variscan strain
in Ireland, including lithological competence, basement fabric and ba
sement-cover thickness. From this, the difficulties of recognizing Var
iscan 'fronts' and 'fold belts' are emphasized. In order to determine
whether all putative Variscan strain is indeed Variscan in age, new ti
me-temperature data (vitrinite reflectance; apatite fission track popu
lations) are discussed, along with offshore data. A case is then prese
nted for recognizing quite distinct episodes of both Variscan and post
-Variscan heating and deformation. Some of the implications for the Va
riscides to the east are briefly examined, and the suitability of a re
gional 'escape tectonics' model is tested.