Defiance of Duskendale
The Defiance of Duskendale was a landmark event during the reign of Aerys II. It began as a refusal of a town charter and certain rights for citizens and ended with the extirpation of one noble family and a severe rift between the King and the Hand of the King, Lord Tywin Lannister.
According to semi-canon sources, Lord Denys Darklyn asked King Aerys II for certain rights for his citizens and a new town charter for Duskendale. He refused and Lord Denys refused to pay taxes to the crown. This led to an escalation of events, some say driven by the poisonous words of Lady Serala, the wife of Lord Denys, that saw the capture of King Aerys. During the capture, Ser Symond Hollard slew Ser Gwayne Gaunt of the Kingsguard.
Lord Denys continued his defiance, even as a large host sat outside his walls, commanded by Tywin Lannister. Tywin's ability to act had been paralyzed when Lord Denys sent word that at the first sign that Tywin intended to storm the town, Lord Denys would kill the king.
The Defiance ended when Ser Barristan Selmy sneaked into the Dun Fort, the seat of House Darklyn, and rescued his king. Lord Denys, no longer having a hostage, immediately opened his gates and begged for mercy. He was beheaded, along with the rest of his family. Not one Darklyn remained alive. The same for House Hollard, who had sided with House Darklyn during the defiance, with the exception of Dontos Hollard who was a child at the time. Ser Barristan asked for his life to be spared and Aerys agreed.
Aerys was never the same afterwards. A severe rift appeared between Aerys and his Hand, who he believed had left him to rot in the dungeons of the Dun Fort. House Darklyn was wiped out and the lands and incomes of Duskendale were given to House Rykker. The lands of House Hollard were taken and the castle torn down.