Christopher Orlet in the Spectator:

THE DIFFICULTY, TO MY mind, is figuring out why the Pope chose to cite this particular quotation from this particular nonentity? Certainly many popes have made similar statements about jihad and Benedict would have had a plethora of popes to quote from. It is therefore instructive to learn more about Manuel II Paleologus. He was, foremost, the antepenultimate emperor of the Byzantine Empire, the successor to the Roman Empire. At the time of his reign (1391-1425) the Muslim Turks had their sights set on the empire’s capital of Constantinople. In 1399, Manuel traveled to England, France, the seat of the Holy Roman Empire, and Aragon seeking assistance from the various monarchs and courts. His visit was a complete bust. The split between the Greek Orthodox and Roman churches proved too wide. Unless the Greeks agreed to join the Roman Church there would be no troops, no assistance, and the Greeks were not about to surrender their autonomy to Rome, not even to save the empire, their religion and their lives.

The result: Within a few years the Turks would take Constantinople, rename it Istanbul, and the Roman-Byzantine Empire would disappear forever from the earth. (In an ironic aside, Manuel’s son Constantine, the last Byzantine-Roman emperor, was killed in battle defending the capital. Legend has it that he discarded his purple cloak and charged into the fray taking so many cuts and blows that his corpse was unrecognizable. Thus, the last Roman emperor was laid to rest in a mass grave.)

I suspect that the Pope was hoping to make the point that unless the West comes together, heals its divisions, and faces the threat of radical Islam together, it may face a similar fate as the Roman-Byzantine Empire. Naturally Benedict couldn’t come right and make such a bald statement — just as Benedict’s predecessor Pope Pius XII had to be similarly circumspect during Nazi rule — so he couched his remark in an obscure reference by a forgotten historical figure. The pope knew that he would have to apologize later for his statement, still he believed it important enough to risk it.