In the days of yore, before the Mighty Netheril Empire was ground to dust, there was a time of great knowledge. The Netherese were powerful magic users, and there was no source of magic that was beyond their reach: They could part the veil of time and space, travel to different planes, and even bring the living back to life.
One of the archmages made great strides into the creation of an entirely new servitor race: The Golem. They would be completely subservient to their creator, or those who had the control rod, and even the most powerful magical spells would not effect them.
As this Master wizard, whose name is lost to the ages, reached his waning years of life, he knew that he must do something to extend his time on Faerun, yet he was known to loath necromancy, as one of his most hated rivals was a Necromancer of no small power.
So this mage, who is known as the Golem Mage in honor of his contributions to the dweomercraft of Golemancy, performed a ritual that none have been able to even begin to duplicate: He used his soul to power one of his creations.
There was, however, something wrong with the ritual. While the mage's life force was preserved, it came at a terrible cost: All of his magic powers, and a great deal of his higher reasoning, were stripped from him.
When he rose in his new body, it is said that all of Faerun shook from the roar of rage that he released.
No one knows what happened next, but as the millennia grew, he became at best a footnote for the rare historical scholar. The world forgot his name, or even that he existed at all.
It wasn't until an adventuring company of renown, The Gilded Fist, came to explore and excavate his laboratory. There, on a table made of the purest crystal that was now cracked and blackened, lay what at first the adventurers believed to be an animated suit of armor, or a Golem.
Instead, as he stirred, he asked them who they were and what they were doing in his laboratory.
Wishing to avoid a battle if they could, and intrigued by his ability to speak, the mage of the group entered into negotiations with the Golem, who lacked a name. It was the Divine servant of the party who suggested his name, Piety (for he was devout in his worship of magic itself). Taking on this name, and having reached an accord, Piety escorted them through his laboratory complex, accessing areas that had long remained dormant.
Once the Gilded Fist has completed exploring the complex, they invited him to come with them, pointing out that he had nothing left here worth staying for. Piety agreed, and joined the Gilded Fist on several of their adventures before striking out on his own when the group broke up.
Now he wanders the new world, learning all he can about both the History of the world and the place his people hold in that history.