Game concept · The Royal Court
Reforge Artifact
The game also links it as Reforge.
From the game's encyclopedia
Some Inventory Artifacts can be Reforged, turning them into Court Artifacts.
You need to have an Antiquarian and pay Gold to Reforge an Artifact, though older Artifacts are cheaper to Reforge.
Just like when you Repair an Artifact, its Durability is restored.
Only Weapons, Armors, Crowns and Regalia can be Reforged, and they always become Pedestal Items.
The game's text for patch 1.20.1.2. Words in blue are entries of the encyclopedia: hover one to read it, as in the game.
Reforge Artifact is an entry of Crusader Kings III's in-game encyclopedia (The Royal Court). The game explains it: "Some Inventory Artifacts can be Reforged, turning them into Court Artifacts." The game also links it as Reforge. Patch 1.20.1.2, from game/common/game_concepts/01_ep1_game_concepts.txt and game/localization/english/game_concepts_l_english.yml.
Source: game/common/game_concepts/01_ep1_game_concepts.txt, game/localization/english/game_concepts_l_english.yml and the English localisation, Crusader Kings III 1.20.1.2.