Daenerys Targaryen (Dany) is the youngest living child of the Mad King, Aerys II. He was the last Targaryen king of Westeros (aka the seven kingdoms), stabbed in the back by his bodyguard Jaime Lannister and replaced by King Robert Baratheon.
Aerys father to three kids- Rhaegar, Viserys and Daenerys
Despite being married (to Elia Martell, Prince Oberyn’s sister), Rhaegar stole away Robert’s beloved, Lyanna Stark, and kept her captive in the Tower Of Joy. You’ll remember that as the place young Ned visited in Bran’s time-travel vision. He ended up being killed by Robert in a battle on the Trident river.