By these charters the Polish nobility was guaranteed the most important fundamental rights and liberties of free citizens, freedom from taxation without its consent, security of person and of property, fair administration of justice, and immunity from arbitrary royal decrees jeopardizing its fundamental rights. Protected by these guaranties the Polish nobility was free to assume and to maintain any attitude it pleased toward the Reformation movement. It could with a reasonable degree of safety defy the king and Pope alike. This is what helps us to understand the spread of the Reformation in Poland in the face of numerous royal edicts against heresy and heretics, with their extremely severe penalties of exile, confiscation of property, infamy, and even death. The economic basis of the ecclesiastical revolt of the Polish nobility, and a most powerful motive therefor, was created by the commercial and industrial transformation of Poland in the sixteenth century. The chief causes leading thereto were three significant historical events, all happening during the second half of the fifteenth century; namely, the conquest of Constantinople by the Turks in 1453, the discovery of America by Columbus in 1492, and Poland’s final complete triumph over the Order of the Teutonic Knights, sealed by the Peace of Thorn in 1466. The first closed the old paths of commerce with the Levant and the Orient; the second opened up new trade routes and new markets to the West; the third added West Prussia with the city of Danzig to Poland, and gave that country control of the lower course of the Vistula River and free access to the sea. Owing to the first two historical events, the commercial centre of Europe shifted from the coasts of the Mediterranean to the coasts of the Atlantic and the Baltic, and the countries lying along these coasts profited by this change.[363] The cities of Antwerp, Bruges, Amsterdam, and Danzig became great emporia of Northwestern Europe. Toward the close of the fifteenth and during the sixteenth centuries the commerce of the Baltic turned out to be the hub of European commerce with the port of Danzig as its centre. From 1466 on the commerce of that city grew steadily. In 1428 the number of ships that arrived in Danzig was 110. In the years 1422, 1429, 1430, and 1432 flotillas of 70, 61, 40, and 59 ships laden with corn sailed from its port. In 1474, 1475, and 1476 the ships arriving in Danzig numbered 403, 525, and 634 respectively. Again, in 1490, 1491, and 1492 the number of ships sailing from Danzig was 720, 607, and 562 for the respective years.[364]