  Systematic surveys of astronomical objects often lead to discoveries, but
always provide invaluable information for statistical studies of well-defined
samples. They also promote follow-up investigations of individual objects or
classes. Surveys using a yet unexplored observing wavelength, a novel technique
or a new instrument are of special importance. Significantly improved observing
parameters (e.g. sensitivity, angular resolution, monitoring capability)
provide new insight into the morphological and physical properties of the
objects studied. I give a brief overview of the important Very Long Baseline
Interferometry (VLBI) imaging surveys conducted in the past. A list of surveys
guides us through the developments up until the present days. I also attempt to
show directions for the near future.
