Which dynasties in ancient China were more open? Those dynasties were very conservative.

The Tang Dynasty was relatively open, but it was actually fine before the Tang Dynasty, because it seemed nothing to remarry before, such as Wu Zetian, the mother of Emperor Wu of the Han Dynasty, and Peacock Flying Southeast, which also wrote that after Liu Lanzhi's divorce, senior officials came to marry her. Since the song dynasty, it has become more and more conservative, mainly because Confucianism has developed to a little abnormal at this time.