There was a brief moment during the installation of Pope Benedict XVI last week when it seemed a historical pity that Rome was no longer under papal rule. That unlikely moment came during Benedict's homily, when he paused to address those outside the Church, including the Jews. "With great affection I also greet . . . you, my brothers and sisters of the Jewish people, to whom we are joined by a great shared spiritual heritage, one rooted in God's irrevocable promises."

His remarks were dramatically different from the words spoken for centuries by newly installed popes as the temporal rulers of the Jews of Rome. The pity is that Benedict's warm sentiments couldn't be received directly by the ancient community that had endured so many difficult years under Benedict's predecessors.

When the popes ruled Rome, an installation included a procession between St. Peter's and the Lateran. Each new pope would be met en route by a delegation of Rome's Jews, who would wish the new pontiff well and present him with a copy of the Pentateuch. The medievalist Ferdinand Gregorovius thought this curious tradition may have begun with the emperors of imperial Rome. That's possible; the city's Jewish community dates to Pompey, and it has seen every pagan emperor as well as every Christian Pontifex Maximus who ruled from Rome. Throughout this entire history, Jewish Rome has been centered along the same bend of the Tiber, having only crossed the ancient Ponte Fabricio from one bank to the other.

Anyway, nearly all the new popes received the Roman Jews' gift of Scripture with the same formula: We affirm the Law, but reject your interpretation of it. Some popes said more and worse, and some are recorded as tossing the gift to the ground. At one time, it was even the responsibility of Rome's Jews to place decorative hangings on various landmarks along the pope's processional route. Among the sites they had to beautify was, invariably, the Arch of Titus, which was notable because the local Jews abominated it; the reliefs still show Titus' triumphal procession of the Temple's treasures. The city's Jews never passed beneath the Arch.

(One pope, by the way, was from the Roman Jewish community. Anacletus II of the converted Pierleoni family held the Papacy from 1130 until 1138 under disputed circumstances; he is today counted among the anti-popes.)

Benedict's warm words during his homily probably didn't surprise anyone; as Cardinal Ratzinger he was reportedly instrumental in arranging John Paul II's historic 1987 visit to Rome's major synagogue. It's easy to understand why that visit is so celebrated. While numerous popes sought good relations with Jewish Rome (Gregory the Great, Martin V, Sixtus V, Clement VII, John XXIII, etc.), many tried to crush it. The worst case was surely Paul IV (1555-1559), whose brief but appalling reign was an authoritarian nightmare. He used the Inquisition to terrorize the city, systemized the censorious Index and burned thousands of books, imprisoned some of his own cardinals, and published Cum Nimis Absurdum, which established a walled Jewish ghetto. When the hated Paul died, the city erupted in a riot; a mob burned down the Inquisition headquarters, decapitated Paul's statue, and threw its pieces into the Tiber. The city's Jews, however, were to remain trapped in their pestilential ghetto for three centuries.

A series of harsh popes was to make life in that ghetto extremely difficult, mandating that Jews wear identifying badges, subjecting them to weekly conversion sermons, tolerating forced baptisms, and preventing them from pursuing any profession or almost any trade. You can walk around the ghetto's old perimeter in less than 10 minutes; it once held 4,000 people. The ghetto was finally abolished only with the end of papal temporal rule in 1870.

Today the Papal States are merely another Roman memory, just as is Titus, and still Rome's Jews remain near the Ponte Fabricio. Close by that bridge stands the city's great synagogue. When John Paul II entered its sanctuary, the ancient congregation rose to welcome him by singing the exaltations of Psalm 150. Praise ye the Lord, they sang. Praise him with the timbrel and dance. Let every thing that hath breath praise the Lord.