Frederick VI
In the older literature, Conrad/Frederick VI's older brother and predecessor Duke Frederick V of Swabia was partly overlooked, because was thought to be identical to as Conrad/Frederick VI, and for this reason he was therefore not counted as Frederick VI, but referred to as Frederick V. The fact that a younger brother born in 1172, the later Conrad II, Duke of Swabia, was given the name Conrad, which had been able to use because Conrad/Frederick VI renaming and which also had a long tradition within the Staufen dynasty, creates additional confusion when identifying these three sons of Frederick I Barbarossa.