The Great Gender War was a conflict among the Androgenans of planet Terra Androgena, fought between the males and females of the species for domination of the planet. For several years prior to the war, tensions had been on the rise as marginalized women agitated for equality. Although they had met with great progress, unrest only increased as they strove for more and as a backlash from certain ultra-conservative males slowed them down. Female-on-male homicide rates rose almost imperceptibly in more populated areas.
The arrival of the Intergalactic Consortium of Angry Housewives and the impassioned speeches given by its members further enraged the female populace and incited terrorist attacks and guerrilla violence all over the planet. Realizing an error in judgment and that the situation was quickly deteriorating, it evacuated most of its members. However, Kayynar Laverĝe, a native of Terra Androgena, remained behind and unified the various skirmishing factions with speeches of her own. Under her charismatic leadership, a vast army of women was formed and began a systematic extermination of men in several population centers.
The men quickly retaliated, and a full-scale war was on, with the exception of some people deep in the jungle who just wanted to be left alone. Brutalities and war crimes abounded on both sides, although for some reason the men were more likely than not to simply give captured females a sound spanking and let them go. In any case it soon became clear that the women would settle for nothing less than total extermination of the men, which raised the interesting question of how they would perpetuate their species in that instance. Some ideas about cloning and such were tossed around before settling on something rather unsettling; a machine called the Gender Bender which transformed women into men just long enough for them to, um, yeah.
With this little problem out of the way there was nothing to dissade the women from accelerating their attacks, and the men found their numbers decimated within weeks. Many of the survivors grouped together and fled into the jungle where they built a city called Machopolis. There they survived in isolation for a few more years before they were discovered, and managed to make a final stand before the vast majority were wiped out entirely. Thus only women remained in society at large and they solved the problem of having no one to boss around by dividing themselves into two castes, "Keepers" and "Stock". The Keepers forced the Stock to have sex with them.
Kind of makes the silent treatment look like a joyride, doesn't it?