Rudolf I, also known as Rudolf of Habsburg (German: Rudolf von Habsburg, Czech: Rudolf Habsburský), was Count of Habsburg from about 1240 and the elected King of the Romans from 1273 until his death.
Rudolf's election marked the end of the Great Interregnum in the Holy Roman Empire after the death of the Hohenstaufen emperor Frederick II in 1250. Originally a Swabian count, he was the first Habsburg to acquire the duchies of Austria and Styria in opposition to his mighty rival, the Přemyslid king Ottokar II of Bohemia, whom he defeated in the 1278 Battle on the Marchfeld. The territories remained under Habsburg rule for more than 600 years, forming the core of the Habsburg Monarchy and the present-day country of Austria.
Rudolf was the first king of the Romans of the Habsburg dynasty, and he played a vital role in raising the comital house to the rank of Imperial princes. He was also the first of a number of late medieval count-kings, so called by the historian Bernd Schneidmüller, from the rival noble houses of Habsburg, Luxembourg, and Wittelsbach, all striving after the Roman-German royal dignity, which ultimately was taken over by the Habsburgs in 1438.
Rudolf died in Speyer on 15 July 1291 and was buried in Speyer Cathedral. Although he had a large family, he was survived by only one son, Albert, afterwards the German king Albert I.