Author: Atarah al'Norahn
Mar Ruois was one of the great cities of the Age of Legends, before the Breaking of the World. According to what information we have, it was the fifth largest/most important city of the Age of Legends (TWoRJTWoT, Ch. 3).
When Mar Ruois was taken by the Shadow during the War of Power, it was burned to the ground and everyone who would not swear to the Shadow was "bound and thrown alive to the flames." Rand has a memory from Lews Therin of the city's fate (TFoH, Ch. 20).