Meraxes

Rhaenys's silver dragon with golden eyes ÔÇö and the first proof that dragons could be killed from the ground.

The beast itself

Meraxes was silver ÔÇö properly silver, bright enough on a clear morning that people looked away from her rather than at her ÔÇö with eyes of molten gold set in a head that was mostly jaw. She was smaller than Balerion and bigger than nearly everything else that has ever flown over Westeros, and unlike the Black Dread she was built for distance rather than weight: long in the wing, light through the body, able to stay up all day and cover more ground before dusk than a rider could on a fortnight of good roads.

Her disposition was showy. She liked height, she liked speed, and she had a habit of dropping through cloud and pulling out low over a town, apparently for no reason at all. Her cry was high and carrying, nothing like Balerion's chest-deep note, and it announced her long before she was in sight. She was the least frightening of the Conqueror's three at rest and the most alarming in the air, and of the three she was the one the smallfolk came out to look at.

Her rider: Rhaenys Targaryen

Rhaenys was the youngest of the three, the one who kept singers and asked them questions, and she flew more than either of her siblings did ÔÇö often alone, often for no stated purpose, over kingdoms that had not yet decided whether they were at war with her family. The pair of them were the Conquest's eyes. She scouted the Reach before the Field of Fire and flew the right of the line during it; she went over the Vale, over the Riverlands, and down to Sunspear before anyone had told her to.

The bond, from outside, looked like enjoyment, which nobody could say of Balerion and Aegon. Rhaenys named her for a Valyrian god and treated her as company. When she flew into Dorne and found Sunspear waiting for her with its gates open and its shadow city empty of anyone worth threatening, it was Meraxes she brought down into the courtyard, and the old princess who received her is supposed to have remarked on the animal before she remarked on the woman.

The war she was flown into

Dorne was the one campaign the Conqueror's dragons could not solve, and Meraxes flew most of it. The Dornish would not put an army in a field to be burned or shut themselves in a castle to be roasted out of it; they emptied their keeps, went into the sands, and let the fire fall on stone and sheep. Three of the great Dornish seats were burned and it changed nothing at all, because there was nobody in them.

So the war became a matter of flying back and forth over a country that refused to be at war in the way the Targaryens understood the term, looking for something worth burning. The lords of the Marches called it patient work. The riders, one suspects, called it something else.

What became of it ÔÇö if an ending is written, it is here. Spoilers.

Over the Hellholt in 10 AC, a scorpion bolt found Meraxes' eye. Dragon and rider fell together onto the castle below. It was the single most consequential shot in Westerosi history: it ended the First Dornish War, it kept Dorne unconquered for two more centuries, and it told every lord in the world that a dragon was, after all, only an animal with a soft place.