At such a time Sandwich, with its shallow fiord, was sure to afford good shelter to the northern long ships; and isolated Thanet, overlooking the navigable strait, was a predestined depot for the northern pirates, as four centuries earlier it had been for the followers of those mythical personifications, Hengest and Horsa. Long before the unification of England under a single West Saxon overlordship the Danes used to land in the island every year, to plunder the crops, and in 851, when AEthelwulf was lord of Wessex at Winchester, 'heathen men,' says the Winchester Chronicle, with its usual charming conciseness, 'first sat over winter in Tenet.' From that time forward the 'heathen men' continually returned to the island, which they used apparently as a base of operations, with their ships lying in Sandwich Haven; in fact, Thanet must long have been a sort of irregular Danish colony. Still, St. Mildred's nuns appear to have lived on somehow at Minster through the dark time, for in 988 the Danes landed and burnt the abbey, as they did again under Swegen in 1011, killing at the same time the abbess and all the inmates. On the whole, it is probable that life and property in Thanet were far from secure any time in the ninth, tenth, and early eleventh centuries. At least as late as the Norman conquest the Wantsum remained a navigable channel, and the usual route to London by sea was in at Sandwich and out at Northmouth. It was thus that King Harold's fleet sailed on its plundering expedition round the coast of Kent (a small unexplained incident of the early English type, only to be understood by the analogies of later Scotch history), and thus too, that many other expeditions are described in the concise style of our unsophisticated early historians. But from the eleventh century onward we hear little of the Wantsum as a navigable channel; it has dwindled down almost entirely to Sandwich Haven, 'the most famous of English ports,' says the writer of the life of Emma of Normandy, about 1050. Sandwich is indeed the oldest of the Cinque Ports, succeeding in this matter to the honours of Rutupiae, and all through the middle ages it remained the great harbour for continental traffic. Edward III. sailed thence for France or Flanders, and as late as 1446 it is still spoken of by a foreign ambassador as the resort of ships from all quarters of Europe.