What does Head of St. Edmund do in CK3?

Court grandeur baseline +1, Piety +0.3/month (patch 1.20.0.3).

How do you get Head of St. Edmund with the console?

effect create_artifact_edmund_head_effect = { OWNER = root } — runs the scripted effect that makes it, for the character you play (debug mode).

What if the owner can't benefit from Head of St. Edmund?

They get Court grandeur baseline +3 instead.

Court artifact · Pedestal Item

Head of St. Edmund

IllustriousUniqueHoly relicThe Royal Court

Head of St. Edmund is an illustrious pedestal item artifact in Crusader Kings III: Court grandeur baseline +1, Piety +0.3/month. Quality 100 and wealth 100; maximum durability 150, and it does not wear out. Made on 869.11.20 for Eadmund of East Anglia in Blything. At game start it goes to the holder of England (starts from 924.1.1) — needs The Royal Court. It needs The Royal Court. Patch 1.20.0.3, from game/common/scripted_effects/01_exp1_historical_artifacts_creation_effect.txt.

Quick answers (3)

What does Head of St. Edmund do in CK3?: Court grandeur baseline +1, Piety +0.3/month (patch 1.20.0.3).
How do you get Head of St. Edmund with the console?: effect create_artifact_edmund_head_effect = { OWNER = root } — runs the scripted effect that makes it, for the character you play (debug mode).
What if the owner can't benefit from Head of St. Edmund?: They get Court grandeur baseline +3 instead.

Edmund demanded he would become a Saint from the moment of his birth. Legends tell he was a King of East Anglia who volunteered as a sacrifice to the Vikings rather than let his people be slaughtered by them.

Effects

Court grandeur baseline+1
Piety+0.3/month

Also gets random bonuses when it is made, from add_scaled_artifact_modifier_devotion_effect — the bigger ones at higher rarity.

For an owner who can't benefit from it

The template gives these instead of the effects above when its “can benefit” check fails:

Court grandeur baseline+3

Who can benefit (can_benefit) (1 line of game script)

christian_artifact_access_trigger = yes

As written in game/common/artifacts/templates (christian_relic_template).

Counts as a holy relic for (is_holy_relic) (6 lines of game script)

OR = {
	religion = religion:christianity_religion
	main_rite = {
		rite_has_parameter = christian_syncretic_actor
	}
}

As written in game/common/artifacts/templates (christian_relic_template).

History and who has it

Made on 869.11.20 for Eadmund of East Anglia in Blything.
Kept with the title England from 955.11.24.
At game start: the holder of England (starts from 924.1.1) — needs The Royal Court.

How it is made

The game creates it with the scripted effect create_artifact_edmund_head_effect. In the console (how to open it), this gives it to the character you play:

effect create_artifact_edmund_head_effect = { OWNER = root }

Built from the effect's file; not run in the game by us.

Source: game/common/scripted_effects/01_exp1_historical_artifacts_creation_effect.txt, common/modifiers (edmund_head_modifier), common/artifacts/templates (christian_relic_template) and the English localisation, Crusader Kings III 1.20.0.3.