Charlemagne's Jerusalem

On Christmas day in 800, Pope Leo III crowned Charlemagne emperor of the Holy Roman Empire. At the ceremony, which took place in Rome, the king was presented with the keys to the Church of the Holy Sepulchre and a banner of Jerusalem. Charlemagne’s decision to be crowned on this date may have been motivated by widespread apocalyptic expectations that the year 800 would usher in a new epoch in human history. And it was against this background that Charlemagne established intensive contacts with Harun al-Rashid, the Abbasid caliph whose empire included the province of Greater Syria. The ties between Charlemagne and Harun al-Rashid were due, at least in part, to shared interests—the principle that the enemy of my enemy is my friend. For Charlemagne, the Abbasids helped keep the Byzantine Empire in check, while for Harun al-Rashid, the Frankish king was a buffer against the threat posed by the remaining Umayyads—the previous regional Islamic dynasty—in Spain.