See Selecting councilors for artifact-hunting abilities. Artifacts can be stolen from religious leaders while in a monastic society.For important yet destructible artifacts, it is recommended to grant a castle to avoid the 50% chance of artifact destruction. Revoking a vassal down to baron tier will force them to use agnatic succession. You may be able to exhaust the line of succession of vassals through assassination or granting temples to heirs.Use the character finder to search for the name of an artifact.