Kalag Ka'Hurst founded the Crossing Thieves Guild around the start of the Elanthian Calendar, just as the Dragon Priest war was ending. All guild leaders following have taken the name "Kalag" as their own. For awhile the most recent leader, Varsyth, stated he will not follow in that tradition, but eventually succumbed to it on 26 Shorka 393 (February 4, 2009). Kalag's tale is found in two books residing within the Crossing Thieves Guild library:
The memoirs tell of how Kalag first came to River Crossing, fleeing his hometown which had been beset by famine. Kalag came across an old man being attacked in the streets and helped fight with the old man. After the encounter Kalag learned the man was a well-known locksmith named Lyanothe, who then offered to teach Kalag many skills in return for Kalag's work as a runner and businss partner.
One day their hideout was discovered and Kalag proposed they move to the sewers, for its easy access to anywhere in the city and its superior defensibility from foes. Kalag and Lyanothe became well known and opened their home to locksmithing students. This band of students began cross-training each other in skills that collectively made them qualified thieves. Kalag proposed they form a Thieves Guild and bring in other members from around the town that were engaged in criminal enterprises.
Kalag planned to have the guild recognized by the city council, but then the Dragon Priest army came to town. The Thieves Guild united against the army and their cunning helped defeat the Dragon Priests. Their actions and some support from the shrewd Trader guildleader earned them official acknowledgement by the city. And thus the Crossing Thieves Guild was formed.