For many centuries the houses of the villeins and cottiers did not alter very much in their general plan. You will remember that in those old pit-dwellings the hearth and its fire were the centre of the home. The room, or space round the fire, gradually became larger, especially in the houses of the thanes and eorls, till we get the hall, with the hearth in the middle and the hole in the roof to let out the smoke. All through the later Saxon and Danish times, and in the Norman period, the hall was the most important part of the house. As the years went on, and the style of building altered, the walls, the windows, and the roof became more beautiful and ornamental, becoming most magnificent in the fourteenth century, or Decorated Period. Gradually other buildings were added to the hall for comfort and convenience. [Illustration: _Diagram of the Shape of a Villein's House_] So far as we know, the house or hut of the villein was a very simple affair before the time of the Norman Conquest. Two pairs of poles were set up, sloped, and joined at the top, and connected by a ridge pole as shown in the illustration. The space between was then filled in by other poles and wattle-work. This was plastered with clay, and covered with turf or rough thatch. There seems to have been a pretty regular length for this building, which was long enough to take four stalls for oxen. That required about sixteen feet and was called a "bay". The villein and his oxen were all housed under one roof at first. When another bay was added, the size of the house was doubled, and so on. In the course of time the houses were improved; side walls were raised of wood framing, and the sides were filled in with wattle and covered with clay. [Illustration: THE OLD PALACE, HATFIELD [See page 71]] As the years went on, these houses or huts grew out of date, and were replaced by others in much the same style, but gradually improving in comfort and workmanship. In the villages there was not much alteration down to the fourteenth century. When a house in a manor or village was pulled down, and was to be rebuilt, the manor court kept a sharp eye upon the building operations to see that the new walls did not encroach upon the highway, or upon the lord's land. No addition could be made to the house without the consent of the overlord. Customs in the villages changed very, very slowly, and so it is that, though the houses in out-of-the-way villages have been rebuilt over and over again, there are many lath-and-plaster houses standing now round village greens, built between two and three hundred years ago, on old foundations which date back to Saxon times.