The Brenna is a tributary of the Gelene river in northern Sabadell. The farms around the stream were ruled by Risfou, who was a son in law of Chief during the Everguardian Period. When Chief signed an agreement with Everguard, the agreement was sealed with weddings – one of them being Risfou's only child, his daughter Irmgard, to a wealthy family in Gelene. After Risfou's death, his estate was inherited by his daughter. But since she lived in Gelene, she needed a supervisor and appointed her cousin, Reynold the Fox, as bailiff. He earned his nickname as a cunning defender of the border region – especially when operating behind enemy lines when the keep on hill Sabadell was besieged.

Reynold was succeeded by his son, Meginhard the Falcon, who earned his nickname as a scout to the Astrumese army. After the Great Monster Invasion, his son, Reynold the Boar, joined Westgard to reclaim his heritage. In Gelene he met the Atamaran Gerulf, who would become his closest friend. Together they fought many battles in the service of the house of D Luffy, but Reynold and his brother Waldger died in YD 52 at the Battle in Farrowfield. Reynold had three sons with his first wife: Meginhard, Roland and Egbert. He also had a daughter, named after her mother: Adela. When his wife died giving birth to Egbert, Reynold remarried to Liutgard, a sister of his friend and advisor Gerulf. He got another son with her, named Everhard.

Meginhard was the first to use the name Brennaborg, when he completed the keep he was ordered to build by his Lord Marcus D Luffy, whose daughter he had married. This resulted in him being granted the county of Sabadell, which allowed him to play a major role during the Seiferic Expansion and he would eventually even be promoted to Lord Commander and receive the Shrine of Seeklander. Although he performed poorly during the Astrumese Succession War, Meginhard had brought fame to the family, allowing his siblings and cousins to obtain their own fiefs and even receive positions in foreign governments. All of them would bring a copy of the Journal of Meginhard. Thus Meginhard would not only be the namegiver of the family, but also the spiritual father of all who would come after him.