For centuries, the dragonlords vied with one another for power while the Freehold held sway across Essos.

To keep their bloodlines pure, the Valyrians practiced incestuous marriage, ideally brother to sister.

The Targaryens were not the mightiest of the dragonlords.

Emma Darcy as Queen Rhaenyra Targaryen in House of the Dragon promotional artwork

Image via HBO

Her father, Aenar, took her vision to heart.

The other dragonlords paid no heed to Aenars flight.

But twelve years after the Targaryens departure, the Doom came to Valyria.

The ruins of Old Valyria in Game of Thrones

Image via HBO

All Fourteen Flames erupted as one, though no one knows why.

Within a single day, Valyria was reduced to smoldering ruin, the power of the Freehold shattered.

With it went the Valyrian knowledge of magic and of crafting the Valyrian steel swords coveted throughout the world.

A dragon breathing fire in season 7 of ‘Game of Thrones’

Only the Targaryens survived.

That changed with the ascendency of Aegon Targaryen and his sister-wives Visenya and Rhaenys.

This trio found Westeros divided into its Seven Kingdoms, almost always at war with one another.

Emilia Clarke as Daenerys Targaryen atop her dragon, Drogon, in Game of Thrones

Image via HBO

The site would eventually grow into the Kings Landing ofGame of Thrones.

Aegons ravens preceded him, bringing to all kings and lords his claim to be their sire.

Nor was Aegons coming wholly unwelcome.

Matt Smith and Emma D’Arcy in House of the Dragon

But once his conquest was mostly complete, he worked to ensure peace and unity among his kingdoms.

His sister-wives arranged countless marriages to interknit the realm.

The institution of the Kingsguard was created.

House of the Dragon

But except for Dorne, Aegons rule was uncontested.

Jaehaerys: The Greatest of Targaryen Kings

His two sons would not be so fortunate.

Jaehaerys and Alysanne ruled the Seven Kingdoms for over 50 years,outliving many of their children.

Game of Thrones

However, this meant that Jaehaerys was left without a clear heir.

And it is there thatHouse of the Dragonbegins…