The Ruling Queens of Númenor were Dúnedain women who ruled the kingdom of Númen

The Ruling Queens of Númenor were Dúnedain women who ruled the kingdom of Númenor. Out of its twenty-five rulers, only three were female. In the early days of Númenor, succession followed the principle of agnatic primogeniture that is, rule passed to the oldest male offspring of the King. Tar-Aldarion, the sixth ruler of Númenor, had only one child: a daughter, Ancalimë. To prevent the throne from passing to his nephew, Soronto, he changed the law to allow full cognatic primogeniture, under which rule would pass to the oldest child of the ruler, whether male or female. (x)