Great Houses
The most influential and dominant families on the planet of Serenno were known as the Great Houses, numbering seven in total. These families included House Serenno, House Malvern, House Borgin, House Hakka, House Demici, and [House Nalju]. Throughout Serenno's history, House Demici and House Nalju were the most significant noble houses, attracting alliances from the other houses. However, House Serenno held the supreme authority on the planet, lending its name to the world itself. Specifically, the leader of the Serenno family, bearing the title Count of Serenno, presided over all other noble houses on Serenno.
To function as the executive arm of the Serenno government, the Great Houses formed a council comprised of members from each of the seven houses. This council was established by Serenno, the very person who spearheaded the resistance against the Sith Empire during the Battle on Serenno. Serving as an advisory body to the Count in power, the council managed the daily operations of Serenno and its surrounding system. By 90 BBY, the council's headquarters were located within the Great Assembly House, situated in Carannia, the capital city.
Behind the scenes
The Great Houses received their initial, albeit indirect, mention within the current Star Wars canon in De Agostini's Star Wars: Build the Millennium Falcon magazine, specifically in the seventieth issue, released around May 4, 2016. Their first direct appearance occurred in the 2019 audiobook Dooku: Jedi Lost, authored by Cavan Scott. Within the Star Wars Legends continuity, the Great Houses of Serenno were initially featured in the 2007 novel Darth Bane: Rule of Two, penned by Drew Karpyshyn.
The seventieth issue of Star Wars: Build the Millennium Falcon erroneously stated that the Great Houses consisted of only six houses.