  A review is presented of the past 165 years of observation of the 4-day
Cepheid Polaris, including the exciting results of the last 50 years, an
interval that has produced three orbital solutions for the spectroscopic binary
subsystem, recently resolved by HST, parameters for the optical companion,
precise measurement of the star's trigonometric parallax and angular diameter,
evidence for a rapid increase in its pulsation period, and observations of the
dramatic decline and recent partial recovery of its light amplitude. There has
been considerable discussion about the exact nature of the star, with potential
resolutions summarized here. It is also noted that many of the star's
characteristics are shared by a small number of other Cepheids that display
rapid period increases identical to those predicted for stars in the first
crossing of the instability strip, small light amplitudes, and intrinsic colors
typical of variables lying near the center of the strip, where Cepheids of
largest amplitude reside. While all members of the group appear to display the
canonical traits of first crossers of the instability strip, Polaris has one
unique peculiarity: a brief hiatus in its monotonic period increment between
1963 and 1966 during which the pulsation period underwent a dramatic decrease.
Has the average brightness of the Cepheid also increased over the last
millennium?
