  The discoveries of the radio source Centaurus A and its optical counterpart
NGC 5128 were important landmarks in the history of Australian astronomy. NGC
5128 was first observed in August 1826 by James Dunlop during a survey of
southern objects at the Parramatta Observatory, west of the settlement at
Sydney Cove. The observatory had been founded a few years earlier by Thomas
Brisbane, the new governor of the British colony of New South Wales. Just over
120 years later, John Bolton, Gordon Stanley and Bruce Slee discovered the
radio source Centaurus A at the Dover Heights field station in Sydney, operated
by CSIRO's Radiophysics Laboratory (the forerunner of the Australia Telescope
National Facility). This paper will describe this early historical work and
summarise further studies of Centaurus A by other Radiophysics groups up to
1960.

Instrumentation and Methods for Astrophysics;Solar and Stellar Astrophysics;History and Philosophy of Physics