migration_settle_down_obedient_vassal_effect

migration_settle_down_obedient_vassal_effect = {
	scope:actor = {
		ordered_in_list = {
			variable = obedient_vassals
			order_by = {
				value = 1
				domicile ?= {
					add = herd
				}
			}
			limit = {
				is_landed = no
			}
			save_scope_as = current_vassal
			add_to_list = settled_vassal
		}
		remove_list_variable = {
			name = obedient_vassals
			target = scope:current_vassal
		}
	}
	change_title_holder = {
		holder = scope:current_vassal
		change = scope:change4
	}
	set_variable = {
		name = migration_previous_culture
		years = 5
		value = culture
	}
	set_county_culture = scope:current_vassal.domicile.domicile_culture
	set_county_rite = scope:current_vassal.domicile.domicile_rite
	scope:current_vassal = {
		change_liege = {
			liege = scope:actor
			change = scope:change4
		}
	}
}

As written in game/common/scripted_effects/09_dlc_mpo_scripted_effects.txt.