  We present a compilation of spectroscopic observations of the sgB[e] star CI
Cam. This includes data from before, during, and after its 1998 outburst. The
object shows a rich emission line spectrum originating from circumstellar
material, rendering it difficult to determine the nature of either star
involved or the cause of the outburst. We collate pre-outburst data to
determine the state of the system before this occurred and provide a baseline
for comparison with later data. During the outburst all lines become stronger,
and hydrogen and helium lines become significantly broader and asymmetric.
After the outburst, spectral changes persist for at least three years, with
FeII and [NII] lines still a factor of ~2 above the pre-outburst level and HeI,
HeII, and NII lines suppressed by a factor of 2-10. We find that the spectral
properties of CI Cam are similar to other sgB[e] stars and therefore suggest
that the geometry of the circumstellar material is similar to that proposed for
the other objects: a two component outflow, with a fast, hot, rarefied polar
wind indistinguishable from that of a normal supergiant and a dense, cooler
equatorial outflow with a much lower velocity. We suggest that CI Cam is among
the hotter members of the class and is viewed nearly pole-on. The nature of the
compact object and the mechanism for the outburst remain uncertain, although it
is likely that the compact object is a black hole or neutron star, and that the
outburst was precipitated by its passage through the equatorial material. We
suggest that this prompted a burst of supercritical accretion resulting in
ejection of much of the material, which was later seen as an expanding radio
remnant. [Abbreviated]
