Rudolf of Rheinfelden
Rudolf of Rheinfelden (German: Rudolf von Rheinfelden; c. 1025 – 15 October 1080) was Duke of Swabia (1057–1079) and German antiking (1077–1080). He was the son of Count Kuno of Rheinfelden.
In 1057 Rudolf allegedly took advantage of the minority of Henry IV, King of the Romans, by kidnapping Matilda, the king's sister. Rudolf demanded, and received, Matilda's hand in marriage (1059), as well as the Duchy of Swabia and administration of the Kingdom of Burgundy. In 1060 Matilda died, and Rudolf subsequently, in 1066, married Adelheid, daughter of Otto of Savoy. Rudolph's daughter Adelaide married Ladislaus I of Hungary.
Rudolf, who was brother-in-law to Henry IV twice over, at first supported the king's campaigns. He aided him in Thuringia and Saxony and was a primary force in the First Battle of Langensalza against the rebels. However, when the Investiture Controversy broke out and Henry was excommunicated, Rudolf met with several other nobles to decide on a course of action. Despite the lifting of Henry's excommunication in 1077, the rebels continued with their plans. At Forchheim, Rudolf was elected antiking in March. He promised to respect the electoral concept of the monarchy and declared his willingness to be subservient to the pope.
On 25 May, Rudolf was crowned by Archbishop Siegfried I in Mainz, but the people of the city revolted and he was forced to flee to Saxony. This presented a problem, since Saxony was cut off from his duchy of Swabia by the king's lands. He then gave Swabia to his son Berthold and attempted to rectify this situation by besieging Würzburg, but to little effect. Meanwhile, he was deprived of Swabia by the Diet at Ulm in May, and Henry IV gave the duchy to Frederick of Büren, the first Hohenstaufen ruler.
The battle of Mellrichstadt in the following year (7 August) proved indecisive. Rudolf found it difficult to convince the Saxons to fight beyond their borders; they viewed Rudolf as a southerner and distrusted him. He was also frustrated by the apparent reluctance of Pope Gregory VII to recognize his cause. In order to gain and maintain supporters, he was forced to grant large parts of the crown lands, as well as those of the church, to his followers. Nevertheless, things seemed to be improving in 1080. The battle of Flarchheim (27 January 1080) went well in his favor. On 7 March, the pope excommunicated Henry again and recognized Rudolf as king.
Emboldened, Rudolf's forces met Henry's at the Elster River. The battle, which took place on 14 October, would have been a huge victory for the anti-royalists. However, Rudolf lost his right hand in the battle and was mortally wounded in the abdomen. He withdrew to nearby Merseburg, where he died the next day and was buried. The rebellion against Henry soon evaporated.