Frederick I Barbarossa (1122-1190) was a German Holy Roman Emperor noted for his involvement in the Third Crusade (1189), a massive expedition in conjunction with the French, led by king Philip Augustus, and the English, under Richard the Lionheart. He organized a grand army of (by contemporary historians' reevaluation) of 15,000 men and 3,000 knights and set out on the overland route to the Holy Land. The emperor saw his unfortunate death in 1190 when he drowned in the Saleph river after a refreshing swim....in his armour...yes. Frederick's death plunged his panicking army into chaos and only a handful actually arrived in Acre.
Legend, however, says he is not dead, but asleep with his knights in a cave in the Kyffhäuser mountain in Thuringia or Mount Untersberg in Bavaria, Germany. When the ravens cease to fly around the mountain he will awake and restore Germany to its former golden age. The emperor's red beard must wrap three times around the perimeter of the table at which he sits before he is to wake. TV tropes informs me that it has only grown twice around thus far :P
A work in progress of Frederick, pondering the ravens as they circle skyward.
Final Composition sketch and initial concepts for Frederick I Barbarossa: