If string theory controls physics at the string scale, the dynamics of
the early Universe before the GUT era will be governed by the low-ene
rgy string equations of motion. Studying these equations, we find that
depending on the initial conditions when the stringy era starts, and
on the time when this era ends, there are a variety of qualitatively d
istinct types of evolution. Among these is the possibility that the Un
iverse underwent a period of inflation. A by-product of this analysis
is the observation that it is often possible to erase any evidence of
a dilaton at late times.