The Guardian publishes an extract from Richard Gott's new book, in which he works himself into a lather over the British Empire. It's somewhat overwritten, but that's not the same as overstated; the thrust of the piece is irresistible: that, however much we allow ourselves to be flattered by talk of good intentions or absence of mind or by comparisons with the Belgian Congo, an empire is necessarily violent and oppressive. (The best short version of this argument I know is Sven Lindqvist's 'Exterminate all the brutes'.)
A striking sentence towards the end, though:
The rebellions and resistance of the subject peoples of empire were so extensive that we may eventually come to consider that Britain's imperial experience bears comparison with the exploits of Genghis Khan or Attila the Hun rather than with those of Alexander the Great.
Why let Alexander off the hook? In the New York Review of Books, Mary Beard questions the greatness:
In a now fragmentary passage of his treatise On the State, [Cicero] seems to have quoted an anecdote that would turn up again, almost five hundred years later, in the pages of Saint Augustine. The story was that a petty pirate had been captured and brought before Alexander. What drove him, Alexander asked, to terrorize the seas with his pirate ship? “The same thing as drives you to terrorize the whole world,” the man sharply replied. There were plenty of acts of terror he could have cited: the total massacres of the male population after the sieges at Tyre and Gaza; the mass killing of the local population in the Punjab; the razing of the royal palace at Persepolis, after (so it was said) one of Alexander’s inebriated dinner parties.
It seems to have slipped Gott's mind momentarily that empires rely on propaganda, projecting an image of relatively benign power, as much as on brutality.