A named votive crown of later Lombard and imperial rite, with an inner iron band. Not Pschent, not the Golden Stool, not Mascapaicha, and not a generic crown.
Also known as Corona Ferrea
Iron Crown of Lombardy is historically related to Iron.
Twining seats the Iron Crown among Christian royal-reliquary crowns tied to sacred legend — Iron Crown speech, not a generic diadem alone.