Brynjolf is a Nord NPC in Skyrim.
Brynjolf is second in command for the Thieves' Guild in Skyrim. He is second only to Mercer Frey, the present Guild Master.
Brynjolf is a member of the Thieves Guild in Riften in the game The Elder Scrolls V: Skyrim
If you want to join the Thieves Guild you can seek him out in the Riften market or in the inn. He will give you a mission to test your capabilities, A Chance Arrangement, and then invite you to join the thieves guild.
2 Daggers, clothes, gold