Rudolph I (also known as Rudolph of Habsburg) (German: Rudolf von Habsburg, Latin: Rudolphus, Czech: Rudolf Habsburský) ((1218-05-01)1 May 1218 – 15 July 1291(1291-07-15)) was King of the Romans from 1273 until his death. He played a vital role in raising the Habsburg dynasty to a leading position among the Imperial feudal dynasties. Originally a Swabian count, he was the first Habsburg to acquire the duchies of Austria and Styria, territories that would remain under Habsburg rule for more than 600 years and would form the core of the Habsburg Monarchy and the present-day country of Austria.
Rudolph was the son of Count Albert IV of Habsburg and Hedwig, daughter of Count Ulrich of Kyburg, and was born at Limburg Castle near Sasbach am Kaiserstuhl in the Breisgau region. At his father's death in 1239, he inherited large estates from his father around the ancestral seat of Habsburg Castle in the Aargau region of present-day Switzerland as well as in Alsace. In 1245 Rudolph married Gertrude, daughter of Count Burkhard III of Hohenberg. As a result, he became an important vassal in Swabia, the former Alemannic German stem duchy.