Persion

Persion is a dragon hatched in Westeros by Elaena Targaryen and Daemon Targaryen, the grandparents of Danae Targaryen, Aeslyn Targaryen, and Rhaegar II Targaryen. He is commanded by Danae Targaryen and his name stems from the High Valyrian word "Perzys" which means fire.

History 

After Daenerys Targaryen failed to reclaim the Iron Throne, and upon the loss of her dragons in Westeros, she fled to Braavos with little to her name but three dragons eggs from Drogon, Viserion, and Rhaegal. With the loss of her dragons the magic needed to hatch the eggs disappeared and at that point the Targaryen dreams of retaking the Iron Throne were replaced with the harsh realities of simply trying to survive. They worked to amass a modest wealth in Braavos and lived there quietly for many years.

Sibling-spouses, Elaena and Daemon Targaryen, inherited the three eggs and returned to Westeros, remaining in a state of poverty and ridicule even in their new home. They sought to bring the dragons of old back into the world and sacrificed their first three children to the flame. The sacrifice of blood and fire was needed in order for men to orchestrate the hatching of dragon eggs and soon there were three small dragons in the world once more. However, the dragons had to be placed in hiding and they remained small in size compared to the dragons of old. 

Three of Elaena and Daemon's living children inherited the dragons upon the passing of their parents. The siblings Naerys Targaryen and Maekar Targaryen married and gave birth to Danae Targaryen and Aeslyn Targaryen, while their brother fathered Rhaegar II Targaryen with a distant cousin. Maekar commanded Persion until the day he died, while Aeslyn's dragon was previously commanded by her mother Naerys. Upon the death of Maekar, Danae took control of Persion. All three dragons had to remain in hiding as House Targaryen had no followers, no armies, and very little land.

The dragons remained small and relatively passive for many years. 

Recent History

First Era

Lady Danae Targaryen retrieved Persion from Sharp Point and traveled with him to the Wall to meet with Grand Maester Orin. While initially described as calm and even lazy, after visiting the ruins of Valyria Persion thrived, growing rapidly in size and becoming fierce.

Second Era

When Danae returned to Westeros, she began attempts to ride Persion, but his wild and temperamental nature made the task challenging.

During a bandit attack in the Stormlands, Persion burned several men to death.

Third Era

Danae fled the capital after a heated argument with the King, her husband, Damon Lannister. She returned to Dragonstone where she began training her dragon in earnest, contemplating severing her alliance with the throne.

While on Dragonstone, Persion killed a number of the Second Sons before Danae was able to subdue him.

At this point his wingspan was described as thirty feet from end to end.

Fourth Era

As the War of the False King reached its climax, Danae decided to aid her husband, Damon. She flew upon Persion's back to Oldtown, passing over King's Landing and causing panics in the process.

At Oldtown, Persion burned the Redwyne and Old Town fleet in the harbor, sinking hundreds of ships and ending countless lives.

The false king, Gylen Hightower, was burned alive atop the Hightower by Persion's dragonfire, setting the tower aflame.

His wingspan was measured at thirty-five feet from end to end.

Fifth Era

While attending a feast at Highgarden, an assassination attempt nearly claimed the life of the Queen. The supposed culprit was executed by way of dragonfire. Persion devoured the man in the courtyard of the castle before an audience of ironborn soldiers.

Upon their return to King's Landing, Persion was placed in the newly completed Dragonpit.

Quotes

"Persion had scales of pearly white, and his horns, spinal crest, eyes, and wing bones were gold, as well as his flame." - Blood and Whispers (Chapter 2)

"What she saw now was not the creature from the Stormlands, a lazy if unruly beast. This... This was a monster." - Sarella Martell

"Larence looked up sharply to see a shadow blot out the darkening sky. “What”- He managed before a thump of wings, as large as the sails of the ships in Blackwater Bay, turned his bowels to water." - Blood and Whispers