Emperor Fredrick I Barbarossa (†1190) takes a ride with his legal team at the Diet of Roncaglia (1154/1158)

Otto of Morena, Historia Frederici I. ed. Ferdinand Güterbock (MGH, Scriptores rerum Germanicarum, N.S. 7; Berlin: 1930) 59: “Cum dominus Fredericus imperator semel equitaret super quodem suo palafredo in medio dominorum Bulgari et Martini, exquisivit ab eis utrum de iure esset dominus mundi. Et dominus Bulgarus respondit, quod non erat dominus quantum ad proprietatem. Dominus vero Martinus respondit quod erat dominus. Et tunc dominus imperator cum descendisset de palafredo super quo sedebat, fecit eum presentari dicto domino Martino. Dominus autem Bulgarus hec audiens dixit hec elegantia verba: ‘amisi equum, quia dixi equum, quod non fuit equum’.

“The Lord Emperor Frederick was riding one day

 on his horse with Lords Bulgarus and Martinus. He asked

them whether he was de iure the Lord of the world. Lord

Bulgarus responded that he was not the owner of all

property. Lord Martinus told him that he was the owner

of all property.”