Now, the wall between the south-west angle and the Walbrook ran along the middle of Thames Street. At the time of its construction there were, therefore, no buildings between the wall and the river. It was built about the middle of the bank, which sloped to the river below, with a narrow stretch of mud at low tide; and above it rose on the hill which still exists, to the higher ground on which the City stood. The breadth of the foreshore varied, but, of course, it was not very great. The first break in the wall was that which allowed for the waters of the Walbrook. Here there was the first port—the Roman port. It may have been the only port, unless, in their haste to complete the wall, which was undoubtedly built under the pressure of panic, the builders deliberately excluded other ports. In that case there may have been many, for nothing was easier than to make a small port, such as the two which still remain of Billingsgate and Queenhithe. A small square space was dug in the mud and shingle of the foreshore. It was maintained by piles placed close together along the three sides of the square, leaving the fourth side open for the ships. Other piles furnished support for wharves and quays. It is therefore quite possible that there may have been other such ports. Puddle Dock may have been one. In the absence of any evidence which might lead one even to form a conjecture, we may believe that Queenhithe, originally Edred’s hithe, was of later, or Saxon, construction; while Billingsgate, close to London Bridge and Bridge Gate, was probably still earlier. What happened, therefore, was this: On the increase of trade, when London was again settled in the sixth century, wharves and quays began to be pushed out on piles upon the foreshore of Billingsgate and Walbrook, or afterwards at other places, when a break in the wall allowed access to the City. When Queenhithe was constructed as an additional port, another break was needed in the wall, and wharves and quays were built along this part of the foreshore as well. The erection of the wharf on piles was speedily followed by the erection of tenements for the people between the wharf and the wall on the bank. The wharf extended laterally; the houses grew up laterally with the wharf; the wharf was pushed out farther upon the mud of the low tide; the wall was broken into here and there at intervals, continually growing less in length. These breaks are marked, possibly, by the ancient stairs, such as those of Paul’s Wharf and Trig Stairs.