Zelphar Thann was the fourth son of Rhammas and Cassandra Thann of Waterdeep and an older brother of Danilo Thann. He served as Tethyr's Count of Rivershire and Estate Chancellor. He was in charge of public works and maintained the siegeworks in the Reclamation Army. However, his passion was wine, so he took care of most of his family's vineyards in the south.