In Japan, the ancient method of making one's own daughter an emperor's bride was practiced, having her give birth to a prince that would be the next emperor, and supporting the prince as his maternal grandfather, thereby increasing and maintaining the political power of his relatives.
日本においては、天皇に自分の娘を嫁がせ次の天皇に成る皇子を産ませ、その皇子を擁立し外祖父として一族の政治力を強化・維持する方法が古代より知られている。