  We present photometry for stars in the Carina dwarf spheroidal galaxy that is
unprecedented in depth, accuracy and spatial coverage. Our data demonstrate
that Carina has had a surprisingly complex evolution dominated by episodic
bursts of star formation. Comparing the color-magnitude diagram with new
theoretical isochrones, we determine that the ages of the ``bursts'' are
approximately 2, 3--6, and 11--13 Gyr. Note that the ``bursts'' and quiescent
phases lasted for <~1 Gyr, which are much longer than the ~0.1 Gyr dynamical
timescale in the galaxy. Each main-sequence turnoff in Carina connects to a
single red giant branch, which tells us that, regardless of age, Carina stars
are metal-poor with [Fe/H]~= -1.86 and a spread in metal abundance of only 0.2
dex. Thus the process of star formation, and the loss of metal-enriched gas
from supernovae-drive winds, in this low mass dwarf galaxy occurred
episodically over many Gyr rather than in a single, brief episode.
