Even if you have went through and completed the ENTIRE Thieves Guild questline, the guild STILL needs your help to grow. What exactly do I mean!? Well, currently, the guild only has ONE city that it is prominent in: Riften .
By doing ADDITIONAL jobs for Vex and Delvin , you can eventually get SPECIAL assignments to help influential customers out in FOUR prominent cities! Doing these special assignments will further the Thieves Guild's rise to power once again, but you will also be rewarded yourself!
For each city that you bring into the Thieves Guild's domain, you will be rewarded (see the rewards down below). The cities that we will be taking over are Solitude, Whiterun, Windhelm, and Markarth (note how these cities are the ones you have to ZONE into...). But how do you do this?
Well; to trigger the special assignments, you have to take jobs from Vex and Delvin. The jobs they will give you can be repeated, and you have to do a total of FIVE or more jobs in a single city before you trigger the special assignment requests. Since you can only go out on TWO jobs at a time (one from VEX and one from DELVIN ) this means you've got quite a few jobs to do...
Note: You can REFUSE to take a job if it doesn't match up to the city that you are trying to gain influence in! Just keep taking and refusing jobs until you get the city you want!
The jobs that count towards this total are the next SEVEN quests listed. That's right, you have a LOT of options on what kind of jobs you want to take, so read all of those section over and start taking jobs so you can get those special assignments (the special assignments are ALSO listed down below, along with some other quest, but I trust you can find what you need easily).
To help keep you motivated, here are the rewards you'll start to see as you start winning over cities:
Note: All of the new merchants are outside of the Ragged Flagon. The fence that I'm talking about is Tonilla.
o ONE CITY DONE:
New Merchant: Syndus (Sells weapons and armor).
Fence now has 1500 gold.
o TWO CITIES DONE:
New Merchant: Herluin Lothaire (Apothecary).
Fence now has 2250 gold.
o THREE CITIES DONE:
New Merchant: Arnskar Ember-Master (Smith).
Smithing Equipment comes with Arnskar.
Fence now has 3000 gold.
Able to start the Miscellaneous Quest "Deliver moon sugar to Ri'saad"
o FOUR CITIES DONE:
New Merchant: Vanryth Gatharian (Sells weapons and armor).
Fence now has 4000 gold.
Able to start the Quest "Under New Management".
The rewards that you get after all four cities are taken are TREMENDOUS, and if you are serious about your thieving, building up the guild again is a GREAT idea. Have fun doing it! I know I did!