This diagram shows a detail of the Imperial House (or House of the Masks) family tree. Some of the following comments are best understood by referring to the fully expanded diagram.

Though brides are sometimes brought into the Imperial House from the Great, for reasons of maintaining blood purity, intermarriage is predominantly sought within the House itself. Thus the prevalence of incestuous unions. Mothers marrying their sons; sisters their brothers.

Whatever his initial blood taint, a God Emperor blood is believed to become perfectly pure at his Apotheosis. This has the effect of purifying the blood of his offspring. But, ultimately, this purity is determined by that of the mother.

The execution of all males whose purity of blood falls close enough to that of an elected candidate, means that there are never many males in the Imperial House of high blood rank. This tends to give Imperial House women a predominant influence on the election of God Emperors.

It is in this context that the very special favour gifted to Sardian by the God Emperor Kumatuya of his own sister, Azurea, as wife can be best understood. Of the Great, Carnelian is of particularly pure blood.