These optional side-quests can help improve your renown, which is invaluable for expanding your diplomatic networks.
When completed, they will give you gold and renown, if you made the right choices.
Below is a list of the known quests in the game as of right now.

To complete the quest, talk to both Istiana and Arzagos to get the location of two nearby hideouts.
Defeat both hideouts to find both pieces.
Support A Faction
Talk to one of these people and give them the Dragon Banner.

Non-Imperial
Imperial
Unify the Empire
Just capture two thirds of all settlements with Imperial/Non-Imperial culture.
He explains that he found your siblings, but was betrayed by one of his own (Galter).
He asks to join you in finding Galter, but wants the pleasure of killing him in return.

Kill all the troops leading to Galter, and you’ll square off against him and some men.
you might choose to either fight him one-on-one, or have your men butcher them.
Radagos will then execute Galter.
Kidnapped Daughter
Journey through different villagers and ask about the kidnapped daughter.
When nearby, you’ll get a prompt that says “they’re still hiding here”.
If stopped by a guard, persuade or bribe the guard.
Once done,save the gamein case the clues given aren’t helpful.
You’ll need to identify the correct suspect standing by the local thugs and accuse him.
Kill him in the arena.
If you had the right suspect, you’ll complete the quest.
Kill an innocent duellist and not only will you fail the mission, you’ll be suspected of murder.
Return to the village and sell them off to complete the quest.
You’ll need to sell 36 of them in total, but this can be done in multiple visits.
Looking for more Mount & Blade II: Bannerlord guides?
Be sure to check out our page onBannerlord sieges, and our overview of theBannerlord combatsystem.