It was much the same with the hundreds. In time they were represented by certain districts, whose borders were known to the people living in them. The hundreds all over the country have not altered their boundaries to any great extent until quite recently. In Hampshire to-day there are thirty-seven hundreds; in Hertfordshire there are only eight; and Middlesex has now the same six hundreds which it had twelve centuries ago when a good part of the county was forest land. As to the time when the hundreds became grouped into shires we cannot speak definitely; the change was brought about gradually and quite naturally. It is not at all likely that all the various kingdoms in England came together on some particular occasion and said: "Now we'll divide all our kingdoms into shires". But the hundreds did become grouped into shires, doubtless because it was necessary that they might act together in matters which concerned all. [Illustration: _Ploughing. From an old Saxon Calendar in the British Museum_] There is nothing like a threatened danger from without to draw men together. We have seen this in a most remarkable way during the Great War. In the tun, no doubt, the villagers fell out with each other; however fairly the strips of land were shared somebody was sure to get what he did not like, and to grumble about it. Some of his fellow-villagers would take his side, and say it was a shame; and others would take the opposite side. But if the cattle belonging to the tun over the hills, or on the other side of the marsh, had been seen on the wrong side of the mark, or boundary which separated the lands of the two tuns, the dispute about the strips in the field would be forgotten, and away the people would go in a body towards the offending tun "to see about it". In much the same way, when the boundaries of a tything or hundred were invaded by another tything or hundred, the differences between the tuns would be dropped, in order to preserve the rights which they had in common. There was strife among the Saxon kingdoms which lasted for many years, especially between the three great rivals, Wessex, Mercia, and Northumbria. The lesser kingdoms were under the dominion, sometimes of one, sometimes of another of these rivals. All this fighting and settling down put more and more power into the hands of the kings. Instead of each village fighting for itself, and leaving all the others to fight for themselves, it was found to be a much safer and wiser policy to join together for common protection. Now if people join together, whether in peace or war, to win a football match or to take a city, somebody must be in authority to give the necessary orders. Hence the power of the king, and the officers acting under him, grew up _by custom_, until the overlordship of the king was so firmly established that no one dared call it in question.