Visby was very fully avenged, but could never really recover from the staggering blow. The ancient port now fell on evil days. The city whose maritime code of laws was to Northern Europe very much what that of Rhodes was to the Mediterranean, slipped so low as to be made, helplessly, the headquarters of Baltic pirates and a pest to the shipping of that sea. The great Margaret (p. 120) cleared them out and annexed the island to Denmark,[79] but her worthless successor, Eric of Pomerania, erected at the southern end of the walls the Castle of Visborg,[80] to be a stronghold for himself. The city suffered further from his blighting presence and piracy sprang up again (p. 132). The saddest blow fell in the seventeenth century when the burghers of Lübeck, former sister city and close ally, plundered and sacked the sinning port and almost ended its being. Gradually it shrank to the quiet little market town that it remains to-day, nestling amid gardens and roses and the lofty ruins of its past. But even yet there is not the sleep of some little English cathedral towns. The railway runs along the quays by the harbour, where is sometimes a busy scene. Southward the chimneys of a factory pour their smoke into the clear air. The vigorous life of an older day still stirs in the picturesque market-place by the ruined Friars' Church. From it wind about to every part of the city narrow streets between garden walls that tunnel here and there under the whitewashed houses. Samuel Laing[81] became quite enthusiastic over the Visby churches. "These are the most interesting Gothic edifices in Europe. Wisby is the Rome of the modern architects who will deal in the Gothic." Possibly this is exaggerated (Laing's knowledge of architecture was small), but there is in it an element of truth. The way in which the church-builders of Gothland departed from stereotyped principles and planned as they were moved is refreshingly original. No series of churches in the world is more deserving of the closest study. This tendency to unusual ground plans and the Norwegian stavekirkes are the chief contributions to Gothic architecture that the northern lands made as the middle ages wore. It gives a most vivid idea of the unity of mediæval Christendom and of the frequency of communication that existed to realise the way in which architecture went through the same general course of evolution in all the lands from Portugal to Norway from the coronation of Charles the Great to the abdication of Charles V.