
“He who controls the sea controls everything.”
As quoted in Australia Defence http://www.australiandefence.com.au/CE98DE40-F806-11DD-8DFE0050568C22C9
Originally quoted by Cicero in Letters to Atticus http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.02.0008%3Abook%3D10%3Aletter%3D8%3Asection%3D4 (10, 8, 4.): ... cuius omne consilium Themistocleum est. existimat enim qui mare teneat eum necesse esse rerum potiri.
Translation http://perseus.uchicago.edu/perseus-cgi/citequery3.pl?dbname=PerseusLatinTexts&getid=1&query=Cic.%20Att.%2010.8: "On the contrary, his view is entirely that of Themistocles: for he holds that the master of the sea must inevitably be master of the empire."