History Knowledge is an Inquisition perk in Dragon Age: Inquisition.

Information

History Knowledge opens up new dialogue options during certain conversations and quests. Additionally, it increases the amount of experience gained for each codex entry unlocked by 50%. This effect is not retroactive, but it will stack with other Knowledge perks as follows:

• One knowledge perk: 75XP per codex entry
• Two knowledge perks: 100XP per codex entry
• Three knowledge perks: 125XP per codex entry
• All four knowledge perks: 150XP per codex entry

Uses

Adamant Fortress

• Here Lies the Abyss - Can be used to persuade some of the Grey Wardens to side with the Inquisition.

Emerald Graves

• Taven - When talking to Taven about Din'an Hanin, this option can be used to give some background information about the tomb.

The Fade/Altar of Mythal

• The Final Piece - In either location, this option can be used to discuss Flemeth's history.

Haven

• Josephine Montilyet - When asking about your background, an elven Inquisitor can choose a historical answer.

Hinterlands

• Master of Horses - Can be used to persuade Master Dennet join the Inquisition.

Redcliffe Village

• Business Arrangements - This perk can be used when speaking to Sister Tanner; however, while it will appear to recruit her as an agent, she will not show up in the list of agents or reduce operation times. To properly recruit her, use the Underworld Knowledge perk instead or have Varric/Cassandra speak to her for you.
• A Healing Hand - Can be used to persuade the healer to help the refugees at the Crossroads.
• In Hushed Whispers - Can be used to ask Clemence about the events in Redcliffe during Dragon Age: Origins. It doesn't seem to offer anything aside from background information.

Therinfal Redoubt

• Champions of the Just - Can be used in dialogue with Envy to point out that historically, mortals attempting to ascend to godhood has not gone well. Does not appear to have any other function.

Skyhold

• Dorian - When asking Dorian about Tevinter, this option can be used to enquire about Corypheus' origins. After Here Lies the Abyss this will unlock the war table operation The Name of Our Enemy.
• Sit in Judgment - When judging Knight-Captain Denam, the Inquisitor can choose to exile him beyond the Sea of Ash, as this was the historical punishment for Seeker officers who failed their charges while stationed at Therinfal Redoubt.

The Descent DLC

Deep Roads

• The Descent - During the opening dialogue, the Inquisitor can use this perk to discuss the Legion of the Dead.

Jaws of Hakkon DLC

Frostback Basin

• Jaws of Hakkon - During the opening dialogue, the Inquisitor can use this perk to discuss Inquisitor Ameridan.
• On Ameridan's Trail - Can be used to name an elven goddess that Bram Kenric is having trouble remembering.

Trespasser DLC

Winter Palace

• Trespasser - Can be used when trying to distract Iron Bull from noticing the Chargers.