The Austrian Emperors were the rulers of the Austrian Empire and later the Austro-Hungarian Empire, which existed from the late Middle Ages until the early 20th century. The most notable emperor was Franz Joseph I, who reigned from 1848 to 1916, overseeing significant political and social changes in Europe. The emperors were part of the Habsburg dynasty, one of the most influential royal families in European history. They played a crucial role in European politics, often through strategic marriages and alliances, which helped expand their influence across the continent.