House Ulgo, a noble family from Alderaan that existed as early as the Cold War, was considered by its loyalists to be the rightful Royal House, boasting a distinguished military lineage. Eschewing the luxurious and indulgent habits common among other Alderaanian noble houses, the Ulgos emphasized family values, discipline, and a sense of duty. A defining characteristic of the Ulgo family was the tradition of military service for every member, resulting in a long line of accomplished officers.
The Ulgos grew increasingly disillusioned with the political gridlock within Alderaan's parliament during the Cold War period. This stalemate arose following the deaths of Queen Silara Panteer and Gaul Panteer (the latter of whom was assassinated on House Ulgo's orders), coupled with the return of House of Thul from exile, supported by the reconstituted Sith Empire. During this turbulent time, General Bouris Ulgo implored the nobles to expel the Thul from Alderaan, but the fragmentation of the houses prevented them from stopping the second Imperial invasion.
In response to these circumstances, Bouris Ulgo proclaimed himself king and openly waged war against House Thul. However, this act of seizing power provoked the other houses, leading them to declare war on Ulgo. Consequently, House Ulgo found itself in a precarious position, besieged on all sides as it struggled to defend its claim to the crown while attempting to impose order on Alderaan through brutal measures, regardless of the cost in lives and resources.
Trask Ulgo, a member of House Ulgo, served as an ensign in the Republic Navy during the Jedi Civil War and perished in battle against the Sith Lord Darth Bandon. Three centuries after his death, Alderaanians, including his descendant Bouris Ulgo, venerated him as a martyr for the Republic.
During the Alderaan Civil War, Bouris Ulgo sought to unite the scattered houses to drive out the formerly exiled House Thul, who had returned with the backing of the resurgent Sith Empire. However, due to the deep divisions among the Alderaanian houses, they failed to recognize the looming threat of a second Imperial invasion that Ulgo foresaw. Consequently, he usurped the throne from House Panteer, which turned all the houses against him, with the exception of House Rist. Eventually, agents of House Panteer removed Ulgo from the throne, but the rest of his house remained steadfast.
Despite these setbacks, House Ulgo participated in a clandestine peace conference with the other noble houses. The summit was nearly derailed by sabotage from Jedi Master Sidonie Garen, who was afflicted with a madness plague and attempted to incite conflict among the houses, until the Barsen'thor cured her. Subsequently, the Barsen'thor facilitated an agreement among the summit participants to establish a truce and reconvene at a later date. To the disappointment of House Teral, there was no discussion of confiscating House Ulgo's lands and armies.
The Ulgo family also appears to have maintained connections to the Outer Rim world of Taris, where they were known as a merchant family with numerous adversaries. The assassin Selven was contracted by an unidentified party, suspected by some to be the rival House of Organa, to eliminate them. Within a single month, Selven completely eradicated the Ulgo family from Taris, earning her a bounty posting from the Republic.