The circular towers of East Anglia (Fig. 29) are only partially analogous to those of Ireland. They belong to various styles from the Norman period onwards, but they are, as just mentioned, attached, not free. Again, while the Irish towers are round because of their development from primitive structures of that shape, the English towers had their form determined by the nature of the building materials available, flint and coarse rubble. Yet there are points of resemblance also. The towers of Norfolk and Suffolk are usually devoid of ornament or individuality. The windows, too, are commonly found in the upper stories, and they face the Cardinal Points[305]. Many of the towers overlook the North Sea, and they were doubtless used for posts of observation, if not as receptacles for treasure. The custom of building defensive towers, whether square or round, in connection with the church, was, as before indicated, probably a legacy from Danish times. But danger did not cease with the piratical raids of the sea-kings. No one who has not lived on the sea-coast, especially on the East or South coast of England, can rightly appreciate the fears which beset maritime folk with respect to invasion. We see the alarm translated into action at the time of the Armada, during the Dutch Wars, and at the period of the Napoleonic struggle, when the martello towers were built, nay, we witness its influence in our own day. [Illustration: FIG. 29. Rushmere church, Suffolk, with Early English round tower. The upper portion has been rebuilt.] Of the three attached round towers still existing in the county of Sussex, that of Piddinghoe (Fig. 30) deserves notice. The immediate explanation of the form adopted by the builders is that the necessity of having stone quoins was thus obviated. But if this be the sole reason, why are not such towers more common in Sussex? Consider the facts. The church at Piddinghoe stands on a natural platform, at a slight, but effective, elevation above the adjacent river Ouse. The tower, built c. A.D. 1120, has the narrow, round-headed windows of the period. One of these, facing West, is six feet from the ground. There is no external doorway. At the time the church was erected there seems to have been no other defensive building. One may fairly suppose that the tower was used as a refuge against pirates and invaders, who would have only a few miles to sail from the mouth of the Ouse in order to reach the village. Another Sussex tower, a square structure in this instance, that of East Dean (Fig. 31), probably served as a partial defence of the rising ground above Birling Gap. [Illustration: FIG. 30. Norman tower (c. 1120) of Piddinghoe church, Sussex, seen from the North-West corner of the churchyard. The tower is built of squared flint, and the short spire is timbered. ]