The Shivers progresses quickly. First the afflicted will get a chill, then shivering that gets progressively worse, until it is so bad that the teeth chatter and the arms and legs convulse uncontrollably. When the end is near, the lips turn blue and the victim begins to cough up blood.
The course of the Shivers is remarkably swift: death can come within a day of the onset of the first chill. Old and young are most vulnerable, though even men in the prime of life can wake up healthy one morning and be struck dead by the next. In the winter of 59 and 60 AC, no more than one in five of those who caught the Shivers ever recovered.
During the reign of Jaehaerys I Targaryen, many suspected that the plague was spread by rats, the small brown kind that sneak aboard sailing ships. It was clear that the disease was not native to Westeros, but spread from some foreign land, as it started in the ports of Westeros. Regardless, the maesters of the Citadel never conclusively determined if the rats were the cause of the spread of the disease.
The Shivers struck Westeros in 59 AC, during the first year of an especially cruel winter plagued by widespread famine. The first cases of the Shivers started in the eastern parts of the Seven Kingdoms, moving across the Blackwater Bay and up the Blackwater Rush, hitting the islands off the crownlands, including Dragonstone and Driftmark. From there, the disease spread across the lands. Oldtown lost a quarter of its population, and King's Landing was hit hardest of all. Half of King Jaehaerys I Targaryen's small council died, along with many of the lords of the Great Houses, a third of the maesters of the Citadel, and the High Septon. King Jaehaerys's own six-year old daughter, Princess Daenerys, fell ill as well, and died a day and a half after first complaining of being cold in 60 AC.
Qarl Corbray, the Lord Commander of the City Watch of King's Landing, succumbed to the Shivers as well, and many men of the City Watch fell ill, resulting in the city becoming truly lawless for a while. The people of King's Landing killed Lord Rego Draz, the master of coin, in 59 AC when he happened upon a hungry and partially drunk crowd on the streets of the city. Enraged by the sight of the Pentoshi, blaming him for the high price of bread during the famine, they attacked and killed Rego Draz, leaving his body on the street. Furious, King Jaehaerys rode forth himself to claim the body of his servant and find and punish the men responsible for his death.
- Lord Edwell Celtigar, the first lord to die.
- His son and heir, who died three days after his father
- Lord Staunton, his wife, and their children.
- Septa Edyth, on Dragonstone.
- Lord Daemon Velaryon's second son and three of his daughters.
- Lord Bar Emmon
- Lord Rosby
- Lady Jirelle of Maidenpool
- Ser Samgood of Sour Hill of the Kingsguard
- Ser Victor the Valiant of the Kingsguard
- Albin Massey
- Qarl Corbray
- Grand Maester Benifer
- Princess Daenerys Targaryen.
- A quarter of Oldtown's population
- The wife and children of Eustace Hightower
- Lord Donnel Hightower
- The High Septon
- Twoscore of the Most Devout
- A third of the archmaesters, maesters, acolytes and novices at the Citadel
- Ser Ronnal Baratheon
- The wives of both of Lord Rogar's brothers.
Sickened but recovered
- Lord Daemon Velaryon, on Driftmark
- Lord Bertrand Tyrell
- Boremund Baratheon
- Jocelyn Baratheon
- Fire & Blood, The Long Reign - Jaehaerys and Alysanne: Policy, Progeny, and Pain.