The Vena system was a star system located within the Expansion Region that contained the planet Vena.
Descended from early Hapan explorers, the Venans had a tradition of maintaining an independent and isolationist stance on their system, remaining unaffiliated from the Galactic Republic, even though they shared a good relationship and the Venans would occasionally trade with the nearby Hapes Cluster.
In 3962 BBY, the Galactic Republic was engaged by Mandalorian Neo-Crusaders in the Vena system as part of the Mandalorian Wars, an ongoing conflict between the two groups. The battle took place because the Mandalorians were advancing through a number of worlds in an attempt to conquer the Core World of Duro. This assault, called Mandalorian Triumph, brought the Mandalorian forces from their territory through the Nazzri system, which they took before launching their attack on the Vena system and winning there as well. Afterward, the Mandalorian forces passed through the Japrael system, where they had taken the planet of Onderon earlier in the war, to rendezvous with forces on Dxun, that planet's moon. The combined army then claimed the Ambria system before continuing Coreward.
Circa 57 BBY, the rise of Baron Kindoro and Baroness Omnino to power on Vena changed their historic isolationist position. Due to the fact that Kindoro and Omnino had been both ambassadors to Coruscant and Alderaan, this contact with outsiders motivated an economic deregulation and active foreign policy, including trade agreements, in order to make goods accessible to the Venan royal family.
This radical shift angered many Venans, who resented the fact that only the royal family was benefitting from the economic opening. The commoners called for a return to isolationism and the old-fashioned values. The regents, unwilling to give in to popular demands, imprisoned the movement leaders and sent them to labor camps. This move aggravated tensions and motivated the emergence of terrorism and sabotage against Venan nobility.
This conflict was worsened with the death of Kindoro, as Baroness Omnino proved herself even more unmerciful than her husband, and waged open, bloody war for years against her subjects, until her death in 37 BBY.