Divide and rule (Latin: divide et impera), or divide and conquer, in politics and sociology is gaining and maintaining power by breaking up larger concentrations of power into pieces that individually have less power than the one implementing the strategy.
The use of this technique is meant to empower the sovereign to control subjects, populations, or factions of different interests, who collectively might be able to oppose his rule. Niccolò Machiavelli identifies a similar application to military strategy, advising in Book VI of The Art of War (1521) (L’arte della guerra): a Captain should endeavor with every act to divide the forces of the enemy. Machiavelli advises that this act should be achieved either by making him suspicious of his men in whom he trusted, or by giving him cause that he has to separate his forces, and, because of this, become weaker.
The strategy, but not the phrase, applies in many ancient cases: the example of Aulus Gabinius exists, parting the Jewish nation into five conventions, reported by Flavius Josephus in Book I, 169–170 of The Jewish War (De bello Judaico). Strabo also reports in Geographica, 8.7.3 that the Achaean League was gradually dissolved when it became part of the Roman province of Macedonia, as the Romans treated the various states differently, wishing to preserve some and to destroy others.
The Frankfurt School and Critical Theory – Cultural Marxism