Lord British's Crown

Lord British's crown is located in Lord Blackthorn's castle in Ultima V. It is one of the Royal Crown Jewels.

In original Ultima V you need to "use" the Crown to wear it, and it doesn't replace any pieces of your character's armor. While it is worn, all magic cast by anyone near the party, other than the party members themselves is completely negated. The Crown was treated as a 'global effect' when in use, and in Ultima V only one such effect could be in use at a time. Thus casting Time Stop, for instance, would remove the Crown's effects--it would have to be Used again (preferrably once Time Stop ran out, or you would end up cancelling the spell before it expired naturally).

In Ultima V: Lazarus the Crown has to be worn by one of the party members as a head piece of armor. It provides 2 defense points and negates all magic cast by anyone but the wearer. The Shadowlords are not affected by the Crown's negation effect.