This bridge established London once and for all. Previously there had been the two ferries—that of Thorney (Westminster) and that of Llyndin Hill, each with its own growing settlement. Either of these rivals might have developed into the foremost city of the valley. But the building of the bridge definitely settled the question and caused the diversion of Watling Street to a course across the bridge, through the settlement, out by way of what was afterwards Newgate, and on to Tyburn, where the old way was rejoined. Having built the bridge, they set to work to make of London a city, as they understood it. In all probability it was quite a flourishing place when they found it. But the Romans had their own thoughts about building, their own ideas of what a city should be. First, they built a citadel. The original British stockade stood on the western hummock of the twin hill, so the Romans chose the eastern height for their defences. This citadel, or fortress, was a large and powerful one, with massive walls which extended from where Cannon Street Station now is to where Mincing Lane runs. Inside it the Roman soldiers lived in safety. Gradually, however, the fortress ceased to be necessary, and a fine town spread out beyond its walls, stretching as far eastwards and westwards as Nature permitted; that is, to the marshes on the east and to the Fleet ravine on the west. In this space were laid out fine streets and splendid villas and public buildings. Along the banks of the River were built quays and river walls; and trade increased by leaps and bounds. Nor was this all. The Romans, as you have probably read, made magnificent roads across England, and London was practically the hub of the series, which radiated in all directions. The old British road through Kent became the Prætorian Way (afterwards the diverted Watling Street), and passed through the city to the north and west. Another, afterwards called Ermyn Street, led off to Norfolk and Suffolk. Yet another important road passed out into Essex, the garden of England in those days. “How do we know all these things?” you ask. Partly by what Roman writers tell us, and partly by all the different things which have been brought to light during recent excavations. When men have been digging the foundations of various modern buildings in different quarters of London, they have discovered the remains of some of these splendid buildings—all of them more or less ruined (for a reason which we shall see later), but a few in good condition. Fine mosaic pavements have been laid bare in one or two places—Leadenhall Street for one; and all sorts of articles—funeral urns, keys, statues, ornaments, domestic utensils, lamps, etc.—have been brought to light, many of which you can still see if you take the trouble to visit the Guildhall Museum and the London Museum. In a court off the Strand may still be seen an excellent specimen of a Roman bath. [Illustration: ROMAN LONDON]