It was narrated from Aishah that :the Messenger of Allah said: “Any woman whose marriage is not arranged by her guardian, her marriage is invalid, her marriage is invalid, her marriage is invalid. If (the man) has had intercourse with her, then the Mahr belongs to her in return for his intimacy with her. And if there is any dispute then the ruler is the guardian of the one who does not have a guardian.”

English translation · Sunan Ibn Majah