Great Spring Sickness
The plague killed tens of thousands in the Seven Kingdoms with the major cities affected the most; it was bad in Lannisport, worse in Oldtown, but worst of all in King's Landing, where four in ten succumbed to it. A strong man could wake up healthy in the morning and die by the evening, so swiftly did the plague strike.
Dorne and the Vale of Arryn did not suffer from the Great Spring Sickness, as they closed off their access roads and their ports to all travellers. Ser Duncan the Tall and his squire, Prince Aegon Targaryen, were in Dorne for the duration of the plague so were unaffected by it.
The plague killed people nobles and smallfolk, including King Daeron II Targaryen and his two most immediate heirs, Princes Valarr and Matarys, as well as the High Septon, a third of the Most Devout, nearly all of the silent sisters in King's Landing, and possibly Daeron's Hand of the King Ser Rolland Uffering, the fourth husband of Lady Rohanne Webber, died in the spring, as did the youngest son of Lord Ambrose Butterwell. Other notable victims include the heir and eldest son of Lord Bracken, and in 210 ᴀᴄ, Lord Damon Lannister.
Lord Brynden Rivers, the Hand of the King to Daeron's successor Aerys I Targaryen, ordered the many bodies be brought to the Dragonpit and burned by the pyromancers. The light of their wildfire pyres could be seen as a dark green glow throughout King's Landing during the night. A quarter of the city burned to the ground.
Many hostages of the Iron Throne, taken from Daemon I Blackfyre's supporters in the aftermath of the First Blackfyre Rebellion, died in the spring. With these kinsmen of their supporters already dead, Lord Gormon Peake and Daemon II Blackfyre felt more comfortable attempting the Second Blackfyre Rebellion.
- The Mystery Knight.
- The Sworn Sword.
- It is unknown whether "...sweet Matarys and Valarr, the Hand." indicates that Valarr was Hand, or that Matarys, Valarr, and an unnamed Hand of the King died during the Spring Sickness.
- The World of Ice & Fire, The Westerlands: House Lannister Under the Dragons.
- The World of Ice & Fire, The Targaryen Kings: Daeron II.
- The World of Ice & Fire, The Targaryen Kings: Aerys I.