The Ascended Caste is a hereditary elite whose wealthy families purchase biological advantages for themselves and their descendants. GeneSys clinics, combinations of life-extending treatments, and contracts governing selective reproduction make those advantages possible. The Caste rests on the conviction that wealth should buy superior descendants as well as a comfortable life.
By the time of Sol Dominion, these families have become more than customers for expensive treatments. Their claim is political: they believe certain family lines are entitled to govern because they have been biologically optimized for the role. Most late-Sol egalitarian movements define themselves partly through opposition to this claimed right to rule.