Frederick Barbarossa crowned emperor

June 18, 1155

Adrian IV crowned Barbarossa in St. Peter's after an uneasy meeting at which the emperor had initially refused to hold the pope's stirrup. Outside, Arnold of Brescia's Roman commune prepared to riot. Frederick left as soon as the ceremony ended and never fully mended his relationship with Rome. The coronation was supposed to inaugurate a partnership between empire and papacy, but instead it revealed the mutual suspicion that would define their dealings for decades.