Agnes was the daughter of Rudolf von Rheinfelden, duke of Swabia, and anti-king of Germany, and his wife Adelaide of Savoy.
[2] After the deaths of her father, Rudolf, in 1080, and her sister, Adelaide, and her brother, Berthold of Rheinfelden, who both died in 1090, Agnes inherited much of the property of her natal dynasty.
[3] Agnes was the founder of the abbey of St. Peter in the Black Forest, burial site for members of her husband’s dynasty (the Zähringer).
They were both interred at St Peter in the Blackforest, an abbey they founded, which became the main burial place for their dynasty.
[5] Agnes had at least eight children with Berthold II, including four sons, and four (or perhaps five) daughters: