Anxieties about foreign invasion were taken so seriously in colonial Sydney that glancing round the Harbour one still sees many reminders of obsolete measures. Its just as well no real enemy put Sydneys big guns and forts to the test. The book quotes many scathing appraisals of their uselessness by contemporary experts. But costly and spectacular training exercises drew huge crowds to see fierce imaginary fighting, as mock invaders were driven away. Illustrated with drawings, maps and photos, this book traces the history of colonial defences. It also summarises invasion literature—sensational new reports, and novels that featured scary attacks, like The Invasion, by W.H. Walker, in which Russian armies flee to their ironclad warships, leaving Sydney ablaze and thousands slaughtered. Dean Boyce, investigating the threats thoroughly for the first time, proves that historians are wrong in writing them off: some fears were justified by the plans and might of foreign navies and raiders, keen on Australias wealth and strategic advantages. Napoleon for one ordered the conquest of Sydney, realising that in 1810 his force would be thwarted by a British blockade of Mauritius.