In his early life, he resided in the old state of Idaho. In the 4th Century PD, Grayson founded the Church of Humanity Unchained and preached against the horrors of technology. He was a "back-to-the-Bible" type, who was very charismatic and attracted many converts; he eventually organized a colony expedition and got it funded with billions of dollars by preaching about finding New Zion and the technology free Garden of Eden.
In 988 PD, he landed with his group on the planet they named Zion and began to build a colony. In 998 PD, just prior to his death, Reverend Grayson decreed that every father in the colony need to beget as many children as possible to help the colony survive. He died and was succeeded by Oliver Mayhew, the first Protector. (HH5)
Austin Grayson was reverred as Saint Austin by both the Grayson and the Masadan branches of the Church of Humanity Unchained.
Several places and things bear the name of the founder of the Church of Humanity Unchained, most notably the planet Grayson itself (renamed from "Zion" shortly after the Reverend's death), as well as its capital, Austin City (HH5), the light cruiser GNS Austin Grayson (HH2), the LAC carrier GNS Austin Grayson and the planetary currency of Grayson, the austin (HH4).