The Ring of Wisdom (or Solomon's Ring) is a ring given to Solomon by God.
The ring holds vast power, and is called by Gilles de Rais "the Grace of God not even the likes of Baalberith and Astaroth can defy".
It holds the power to subjugate demons and with it Solomon is said to have been as powerful as Emperor of Hell.  It also lengthened Solomon's lifespan.
The ring, and it's power - and true wielder, is coveted by both Heaven and Hell.
With the ring Solomon subjugated 72 demons to his will and made them his Pillars, defeated the armies of his brothers and rose to the throne of Israel.
It was passed down through Solomon's bloodline and had been in the possession of the Ethiopian Royal family.
How it came to the Twining family is unknown (it is likely Uriel that brought it), but it was called a heirloom and was in the possession of Kevin until William took it in Pillar 25.
When put on William's finger, it awakens Solomon's consciousness. 
- ↑ Pillar 29
- ↑ Pillar 1
- ↑ Pillar 41, pg 16
- ↑ Pillar 28, Pillar 29