Beag

It was a mark of nobility among the German races — by some considered the origin of our coronets — and had even about it a quasi-religious character in memory of the "holy beag" (holy ring), the oath upon which was tantamount to the oath upon Thorr's hammer.

[...] and the description of that monarch in his anonymous Vita as coronatus lauro probably indicates a beag which was lighter than the formal diadema.