House Targaryen is one of the former Great Houses of Westeros and the previous ruling royal house of the Seven Kingdoms, before House Baratheon took the Iron Throne. House Targaryen’s symbol is a three-headed red dragon on a black background and their motto is “Fire and Blood”.
Once a noble family of the vast Valyrian Freehold, an empire spanning most of the eastern continent, the Targaryens were given control of the island of Dragonstone in the Narrow Sea some centuries ago.
After the obliteration of Valyria in the Doom, the Targaryens launched a devastating invasion of Westeros using three dragons to spearhead their attack. In a short period of time six of the seven formerly-independent kingdoms had surrendered to the Targaryen leader, King Aegon I, unifying the continent under his rule. The last hold-out, Dorne, joined the kingdom through a political and marriage alliance some two centuries later.
The Targaryens adopted the religion and many of the customs of Westeros, but two old Valyrian customs they continued to perform in defiance of public disapproval: Targaryen princes and kings were allowed to have multiple wives and Targaryens were allowed to marry brother to sister, something considered an abominable sin elsewhere in Westeros.
During the increasingly erratic reign of King Aerys II, his son Rhaegar kidnapped Lyanna Stark of Winterfell for reasons unknown. This sparked a massive uprising led by Eddard Stark, Robert Baratheon and Jon Arryn. At the end of this war Aerys and Rhaegar were dead and the Targaryen power-base in Westeros destroyed. Aerys’s youngest two children were taken by Targaryan loyalists into exile in the Free Cities of the east.
The Targaryens have some unusual genetic traits, such as their silver-white hair and an apparent ability to withstand higher temperatures than most people. It is noted that in the latter case, Daenerys Targaryen is specifically shown to have this trait whilst Viserys is not noted as possessing it.
Due to the constant inbreeding insanity has become a common factor in Targaryens. When they ruled the seven kingdoms it became a bit of joke among the people for a coin toss to be held to see if the child would be “mad or great”. Despite this insanity does not dominate the bloodline with Daenerys seen as the exception while her brother is clearly unhinged.
King Aerys’s aunt, Princess Rhaelle, married into House Baratheon. Robert Baratheon and his brothers are her grandsons, giving Robert his claim to the Iron Throne that he pursued during the civil war.
In the booksIn the books House Targaryen moved from Valyria to Dragonstone, apparently in fear of a prophecy predicting the destruction of Valyria a century before it happened. After the fall of Valyria, the Targaryens stayed on Dragonstone for a hundred years, apparently hoarding the strength of their dragons and debating whether to invade Westeros or to attempt to seize control of the Valyrian colony-states which later became known as the Free Cities. In the event, they chose to invade Westeros instead.
House Targaryen ruled Westeros for 283 years, during which time they survived substantial civil wars (including the Dance of Dragons and no less than five Blackfyre Rebellions), plague (the Great Spring Sickness) and even an attempted foreign invasion (in the War of the Ninepenny Kings). They were brought down when the Mad King’s insanity became too dangerous to be ignored.