But it was now anything but a flourishing city. The Danish invasions for a while destroyed its prosperity, and as Sir Walter Besant holds, caused the greater part of the population to flee. It was King Alfred who restored London, repaired the broken walls, and brought back the trade. “There were great heroes before Agamemnon,” the poet tells us, “but they found no chronicler to recount their feats.” And in like manner, one may say, the Tower had, no doubt, passages of historic interest before the Norman Conquest, which have not come down to us. It is barely mentioned in the Saxon chronicles. A few Saxon remains are noted by antiquaries. But at the Norman Conquest the continuous and most striking history begins, and continues unbroken. As we look upon it to-day, spite of all the mighty changes which Time has wrought, not only in the surroundings, but in the building itself, the great square keep is the most conspicuous object, and it was built by William the Conqueror. He brought, on the recommendation of Lanfranc, from the monastery of Bec a Benedictine monk named Gundulf, and made him Bishop of Rochester. He had travelled not only over many parts of Europe, but in the East, and was familiar with the beauties of Saracenic art, which he made subservient to the decoration of his monastery, and now brought into use in his new See. He rebuilt Rochester Cathedral, and the noble castle beside it has also been ascribed to him, but this seems to be a mistake. And then the great King set him to work on the London fortress; and he built the White Tower, as we call it, as well as St. Peter’s Church and the old Barbican, the present Jewel House. “I find,” writes Stow, “in a fair register book, containing the acts of the bishops of Rochester, set down by Edmund of Hadenham, that William I, surnamed Conqueror, built the Tower of London, to wit, the great white and square tower there, about the year of Christ 1078, appointing Gundulf, then Bishop of Rochester, to be principal surveyor and overseer of that work.” Gundulf was the greatest builder of his time; several still existent Norman towers in Kent are almost certainly his;[1] but he was also most earnest in the discharge of his episcopal duties, and both Lanfranc and Anselm entrusted much spiritual work to him. Even the rough and brutal Rufus, as well as his brother Henry I, treated him with marked respect. He died in 1108 at the age of eighty-four. The massive Ballium wall, varying from thirty to forty feet in height, was probably also his work.