Codes of chivalry and "gentlemanly behavior" came about in the context of strictly class-oriented patriarchy. Those codes existed not to protect women but to reinforce male status within that hierarchy, with women being the currency of social transaction. And like the Bushido of the Samurai, most of the culture around it was a romanticized retcon of a brutal reality.

There's no historical evidence of a knight ever having rescued a damsel in distress, for instance. It was far more likely for a knight to kidnap women, rape them to "consummate marriage" and take legal possession of their property. And that was just a privilege afforded to noble women who had anything worth stealing.