But here, as elsewhere, as time went on the encroachments of the Persians were a perpetual danger to the Christianity of the East. In 615 Jerusalem fell into their hands. The Jews, whom earlier emperors had, like Justinian, kept in subjection, had grown in the days of Heraclius to be much more powerful in Syria than the Christians, and it was they who secured Jerusalem and gave it into the hands of the Persians; and again, after the Christians had overpowered the garrison, the city was given back to them and to scenes of pillage and outrage; the churches, so splendid as early as the fourth century, and described in glowing language by Procopius in the sixth, were sacked and defiled; the clergy and the patriarch were made captive; the Holy Cross, discovered by the Empress Helena, was sent away into Persia; and "all these things," says the chronicler, "happened not in a year or a month, but within a few days." The ruined churches were, however, restored {101} before long by the alms of the faithful, and it was not long before the Christians themselves were favoured by the Persian king, and Chosroes, in consequence of a council at Jerusalem in 628, legalised, it would seem, the Monophysite heresy as the representative of Christianity. [Sidenote: Reconquest by Heraclius, 622.] The conquest of Egypt followed on that of Syria; and the union of the Coptic Church with that of the Syrian Monophysites was a result, natural and almost inevitable, of the community of suffering between them. Within a few years--his campaign began in 622--the heroic emperor Heraclius won back all that had been lost, utterly defeated the Persians, won back the Holy Rood, restored the patriarch Zacharias to Jerusalem, and returned in triumph to the imperial city. In 629 he went on a pilgrimage to the Holy City, and on September 14th--still observed as the feast of the Exaltation of the Holy Cross--he restored the Rood to the Church of the Resurrection. [Sidenote: Conquest by the Muhammadans.]