The Third House of Betazed was the third oldest house on the planet Betazed. The Third House was one of the most important families in Betazoid culture, whose ancestry could be traced back to the founding of Betazoid society. By the late 2350s, the Third House was headed by Gart Xerx. In 2359, the wedding of Gart's daughter, Chandra, led to the Federation choosing to send a representative. Initially, Mark Roper was to attend the ceremony with his daughter, Wendy, however, a prior engagement led Wendy to attend the ceremony with Lieutenant William T. Riker. (TNG novel: Imzadi)