House Serenno was the dominant family that governed the planet of Serenno, the very world from which their name originated. All other noble houses were subordinate to the leader of House Serenno, who held the title of Count of Serenno. Dooku embraced his heritage after his departure from the Jedi Order, inheriting the position of Count of Serenno. The house's sigil was prominently displayed as an etching within a stained glass window situated at the opposite end of the great hall inside Castle Serenno.
The De Agostini publication Star Wars: Build the Millennium Falcon, specifically its seventieth issue, referred to the house as both "House Dooku" and "House of Dooku". This issue was released around May 4, 2016.
The audio drama Dooku: Jedi Lost, penned by Cavan Scott in 2019, was the first instance of the house being identified as "House Serenno". Scott clarified that "Dooku" serves as a singular name rather than a first or last name. During the development of Jedi Lost, which explored Dooku's history, Scott contemplated assigning the count an additional name but ultimately decided against it. Consequently, Scott has stated that Serennian nobles exclusively use a singular name, while their formal address includes their affiliation with House Serenno. Therefore, Dooku's complete name is not "Dooku Serenno," but he would respond to the official designation "Dooku of House Serenno".