The Abh all go through genetic manipulation before being born to maintain the purity of being an Abh. All Abh are beautiful, with blue hair (which is a requirement for being an Abh) and elven ears. They also have a very long life expectancy: well over 200 years, but they age very little. Thus, a 200-year-old Abh would die looking exactly as they did when they were 25. Abh are also space-dwelling and space-faring. They are born in space and stay there for their whole lives, refusing to so much as set foot on land.
In the Humankind Empire of Abh, there are eight royal families from which an emperor or empress is chosen. In Crest of the Stars, Lafiel is the granddaughter of the current empress, who is from the Clyuve family - Nei Dobrusk, and is, thus, a princess who is potentially in line for the throne.