Speak with Mother then with Bethany or Carver to progress the quest. Enter the southern room and read the book on The Cardinal Rules of Magic then leave the house and enter Darktown. Check the rubble as you enter and head up the stairs to start a fight. Read the book on The Tevinter Imperium to the east and then the Kirkwall - Darktown monument further along.
Head up the stairs to find a sack then head west and speak with Tomwise who will give you the Formula: Debilitating Poison . Further west you can turn in the Locks of the Golden Fool quest. Head back to the northeast and if you can, open the locked doors. Read the book on the History of Kirkwall: Chapter 4 then head back out and enter the Amell Estate Cellar.
Loot the barrel then advance into the next room where you are attacked. Read the book on the History of Kirkwall: Chapter 1 then check the crate in the corner.
The eastern room holds a crate and a barrel with minor items inside. Go north up the steps and fight off more Guards, then open the chest . In the room to the south is a crate , a chest containing a Portrait of your Mother or Tobrius' Documents which starts the quest 'Portrait of the Past' or 'Family Matters' , and a crest of The Amell Family . Leave the room and go south where more attacks occur, fend off the enemies and loot the crate then head south into a small room. Loot the two sacks then read the book History of Kirkwall: Chapter 2 .
Continue west into a large room where a battle ensues against a Master Slaver. There is a large trap going across the room, be sure to disable it at the start of the fight. Focus down the Master Slaver as he can teleport and put a hurting on the group. Afterwards, loot his corpse for the V ault Key and an Imperial Bloodhelm . Open the chest - simple in the corner for the Mask of the Imperium then make your way west. Read the History of the Circle and check the two chests to find Grandfather Amell's Will and Testament and the Ferelden Girded Plating for Carter.
Return to Gamlen's House to complete the quest.
Kicked the slavers out of your ancestral mansion.
Portrait of the Past / Family History
Speak with Bethany after completing Birthright to give the gift and wrap up this quest. Check the Writing Desk to acquire two Secondary Quests called 'The Bone Pit' and 'Loose Ends' if you choose to accept.
If you have Carver in the party then head to The Gallows and talk to Tobrius to finish up with Family History. Return to Gamlen's Home and speak with Carver to wrap up the quest.