London was quite unlike the great metropolis which we now inhabit. Its extent was confined to what is now termed "the city," then surrounded by a wall, built, as it is supposed, about the age of Constantine, and of which a few fragments are existing. All around was open country. Towards the north-east a deep marsh,--the name is yet preserved in Moorfields,--extended to the foot of the Roman ramparts. On the western side of the city, and at the distance of nearly two miles, the branches of a small river which fell into the Thames formed an island, so overgrown with thickets and brushwood, that the Saxons called it "_Thorney_," or the "Isle of Thorns." The river surrounding Thorney crept sullenly along the plashy soil; and the spot was so wild and desolate, that it is described as a fearful and terrible place, which no one could approach after nightfall without great danger. In this island there had been an ancient Roman temple, consecrated to Apollo. And Sebert, perhaps on account of the seclusion which Thorney afforded, resolved to build a church on the site, and he dedicated the fabric to St. Peter the Apostle. This church is now Westminster Abbey; the busy city of Westminster is old Thorney Island, that seat of desolation; and the bones of Sebert yet rest in the structure which he founded. Another great church was built by Sebert, in the city of London, upon the ruins of the heathen temple of Diana. This church is now St. Paul's Cathedral; and Mellitus being appointed the first Bishop by Ethelbert and Sebert, the succession has continued to the present day. _Influence of Christianity._ Before a century had elapsed, Christianity was firmly and sincerely believed throughout Anglo-Saxon Britain; and, in the state of society which then prevailed, the establishment of the true religion became the means of conferring the greatest temporal advantages upon the community. A large proportion of the population consisted either of slaves or of churls or of villains, who were compelled to till the ground for the benefit of their masters. These classes immediately gained the comfort of rest, one day in seven; and they whose labour had hitherto been unremitted, without any pause, except when fainting nature sunk under incessant toil, could now expect the Sabbath of the Lord, as a day of holiness and of repose. So strictly did the temporal laws protect the observance of the seventh day, the right and privilege of the poor, that the master who compelled his slave to work on the Sunday, was deprived of the means of abusing his power,--the slave obtained his freedom.