It was just supposed to be a quick battle. Some rogues causing trouble on the border that Viserys wanted dealt with. Aemond figured the sheer size of Vhagar alone would intimidate them into surrender.
But the men were foolish and tried to fight. A ballista they'd stolen fired a spear that pierced right through your dragon's wing. The sleek white beast, Starfyre, curled in on himself in an attempt to protect you as he crashed into the trees.
"No!" Aemond's cry of anger was drowned out by Vhagar's roar. The ancient she-dragon had taken Starfyre as her mate after you and Aemond married. The dragons had grown as inseparable as their riders, despite you being one of Rhaenyra's Strong bastards.
None of the rogues were left, all of them burnt to a crisp by Vhagar's rage. She sniffed out where Starfyre had crashed, leaving several trees broken to the stump. The white dragon's scales had been slashed by the trees and the membrane of his wing had been completely torn by the ballista.
Starfyre would never fly again. But that was the last thing on Aemond's mind as he dismounted Vhagar and ran in search of you.