  The possible existence of black holes has fascinated scientists at least
since Michell and Laplace's proposal that a gravitating object could exist from
which light could not escape. In the 20th century, in light of the general
theory of relativity, it became apparent that, were such objects to exist,
their structure would be far richer than originally imagined. Today,
astronomical observations strongly suggest that either black holes, or objects
with similar properties, not only exist but may well be abundant in our
universe. In light of this, black hole research is now not only motivated by
the fascinating theoretical properties such objects must possess but also as an
attempt to better understand the universe around us. We review here some
selected developments in black hole research, from a review of its early
history to current topics in black hole physics research. Black holes have been
studied at all levels; classically, semi-classically, and more recently, as an
arena to test predictions of candidate theories of quantum gravity. We will
review here progress and current research at all these levels as well as
discuss some proposed alternatives to black holes.
