When the three sons of Gauldur divided the amulet amongst themselves, they immediately began sacking various settlements around Skyrim.
The quest details the investigation of the Gauldur legend, and the finding and forging of the long lost, ancient Gauldur Amulet. The quest can also be activated by reading a Writ of Sealing in any of the burial locations. A copy can be found on a dead adventurer's body in Reachwater Rock where part of this quest takes place. See here for more information on their locations. This quest can be started by reading the book ' Lost Legends' found throughout Skyrim.
Perhaps someone still knows the truth of this ancient tale. The entire incident was covered up, their names struck from every record. Long ago, the Archmage Gauldur was murdered, and his three sons were hunted down by King Herald's personal battlemage.