Made from an offshoot of the Tree of the Knowledge of Good and Evil in the Garden of Eden, the wood takes various forms across the millennia, becoming an object of reverence, desire and fear for various crowned heads until the early seventh century, when a Christian emperor humbly carries it to its sanctuary in Jerusalem.
WSJ: A Heavenly View From On High | Basilica of Santa Croce | Agnolo Gaddi | By Francis X. Rocca