Valaena Velaryon

Valaena was born into House Velaryon, another Valyrian family settled in Westeros. Through her mother, though, Targaryen blood ran in her veins as well, since her mother came from that very house — the same house her future husband belonged to.

She married her own cousin, Lord Aerion Targaryen, lord of Dragonstone, and through that marriage became lady of the castle built upon the island.

The marriage produced three children, Visenya, Aegon and Rhaenys, who grew up long before anyone knew they would one day cross the narrow sea to bring the Seven Kingdoms under their rule and raise a new dynasty upon them.

That conquest, carried out by her children once grown, made Valaena the mother of the first Targaryen kings and the last woman to hold the title of lady consort of Dragonstone before the island's standing changed.

The known dates leave open another possibility: that Valaena was bound by blood to Daemon Velaryon, either as his sister or his aunt, though the exact tie has never been settled with certainty.