Rudolph belonged to the elder Welf family and was the son of Conrad, Count of Auxerre and Waldrada of Worms. From his father he inherited the lay abbacy of Street Maurice en Valais, making him the most powerful magnate in Upper Burgundy - present-day western Switzerland and the Franche-Comté.
After the deposition and death of Charles the Fat, the nobles and leading clergy of Upper Burgundy met at Street Maurice and elected Rudolph as king. Apparently on the basis of this election, Rudolph claimed the whole of Lotharingia, taking much of modern Lorraine and Alsace - but his claim was contested by Arnulf of Carinthia, the new king of East Francia or Germany, who rapidly forced Rudolph to abandon Lotharingia in return for recognition as king of Burgundy. However, hostilities between Rudolph and Arnulf seem to have continued intermittently until 894.
Rudolph"s relationships with his other neighbours were friendlier.
Rudolf I"s widow, queen Guilla, married in 912 Hugh of Arles.
