Here is the full list of all 12 The Tale of a Common Man achievements.
Deal with your Archnemesis
Kill Jakktar
Rescue Feniel from Murder
Meet Phaltar
Recruit Boulder
Admire the Boat
Kill Pirate Leader
Find the Soldiers in the Haunted House
Kill Bandit Chief
Find Lakeside Resort
Get Rowath to Talk to Doalan's Dad
Rescue Aaydan