A closer look

While other dynasties wasted money on endless wars, the Habsburgs realized that aggressive, strategic incest was a much cheaper way to conquer a continent. Their famous motto literally translated to 'Let others wage war; you, happy Austria, marry.' By marrying their own cousins and nieces at an industrial scale, they successfully locked down the thrones of Spain, Germany, and Italy, though they ultimately paid the price with generations of collapsing genetic health.