Operation Barbarossa, named after Frederick I Barbarossa of Germany, Holy Roman Emperor 1155-1190. An expansionist emperor, imposed order in Germany proper from rival feudal barons, attempted to extend control to northern Italy and the Papacy. In 1188, he joined the Third Crusade along with Philip II of France and Richard the Lionhearted of England. They defeated the Islamic forces at Philomelion (modern-day Aksehir) and Iconium (modern-day Konya), but drowned in freak accident crossing the Calycadnus River (near Goksu) in Cilicia on 10 June 1190. Frederick I Barbarossa - en.wikipedia.org/wiki/Frederick_I%2C_Holy_Roman_Emperor

Since Emperor's body was never brought back to Germany, people of that era heard rumors that Barbarossa was still alive, sleeping inside a subterranean chateau of Kyffhaeuser mountain (caves with marble-like rock formations of anhydrite and gypsum), waiting for the time to defend Germany once again. Some envision him sitting next to marble table, holding his sword and shield standard, awaken every 1000 years by a raven to see if his countrymen is needed to defend the realm.

Originally, this legend referred to Staufan Emperor Friedrich II of Germany, by 16th-century emphasis shifted to Friedrich I. Barbarossa. This 1000-year reawakening theme was also used by the Nazi to project German socio-political re-emergence as a premier world power.

In 1125, Barbarossa became Herzog von Schwaben (Duke of Swabia), German King in 1152, and Holy Roman Emperor in 1155. Common folks supported a strong centralized law-and-order Imperium against aristocratic classes, which fought each other incessantly over ascension rights, land, commerce.

In late-1150s, controversy arose when Pope Adrian proclaimed that Barbarossa only held his domain as a fiefdom of the Papacy and asserted the Pope as supreme religious leader of Catholic Christendom (Eastern Orthodox Christians do not recognize this title). Problems compounded by Italian Lombards refusal to accept German imperial rights over their commercial urban centers and mobilized other Italian cities to join the fight.

Barbarossa retaliated by selecting another Pope to replace Adrian, thus began the Anti-Popes era in which the Papacy was just another resource fought over in European politics. After a series of military campaigns into Italy, Barbarossa forces were defeated at Legnano in 1176 and ended his last efforts to control land south of the Alps. Barbarossa was compelled to accept Pope Alexander III from rival camp to the Papacy and greater political autonomy for Lombardy city states. Battle of Legnano - http://en.wikipedia.org/wiki/Battle_of_Legnano