Construction of the Gothic cathedral started in 1248 under Konrad von Hochstaden. The eastern arm was completed and consecrated in 1322. Construction of the western arm was halted in 1475, and it would remain unfinished until 1880.
In 1074 the commune was formed. By the 13th century, the relationship between the city and its archbishop had become difficult, and after the Battle of Worringen in 1288, the forces of Brabant and the citizenry of Cologne captured Archbishop Siegfried of Westerburg (1274–97), resulting in almost complete freedom for the city. To regain his liberty the archbishop recognized the political independence of Cologne but reserved certain rights, notably the administration of justice.
Cologne effectively became a free city after 1288, and in 1475 it was formally made a free imperial city, a status that it held until annexed by France on May 28, 1796. The Archbishopric of Cologne was a state in its own right within the Holy Roman Empire, but the city was independent, and the archbishops were usually not allowed to enter it. Instead, they took up residence in Bonn and later in Brühl until they returned in 1821. From 1583 to 1761, all ruling archbishops came from the Wittelsbach dynasty. As powerful electors, the archbishops repeatedly challenged Cologne’s free status during the 17th and 18th centuries, resulting in complicated legal affairs, which were handled by diplomatic means, usually to the advantage of the city.
Long-distance trade in the Baltic intensified as the major trading towns came together in the Hanseatic League under the leadership of Lübeck. The League was a business alliance of trading cities and their guilds that dominated trade along the coast of Northern Europe. It flourished from the 1200 to 1500 and continued with lesser importance thereafter. The chief cities were Cologne on the Rhine, Hamburg and Bremen on the North Sea, and Lübeck on the Baltic. Cologne was a leading member, especially because of its trade with England. The Hanseatic League gave merchants special privileges in member cities, which dominated trade in the Baltic Sea and the North Sea. Cologne’s hinterland in Germany gave it an added advantage over the other Hanseatic cities, and it became the largest city in Germany and the region. Cologne’s central location on the Rhine placed it at the intersection of the major trade routes between east and west and was the basis of Cologne’s growth. The economic structures of medieval and early modern Cologne were based on the city’s major harbor, its location as a transport hub, and its entrepreneurial merchants who built ties with merchants in other Hanseatic cities.
Cologne Cathedral housed sacred relics that made it a destination for many worshippers. With the bishop not resident, the city was ruled by patricians (merchants carrying on long-distance trade). The craftsmen formed guilds, which sought to obtain control of the towns. The guilds were governed by strict rules. A few were open to women. Society was divided into sharply demarcated classes: the clergy, physicians, merchants, and various guilds of artisans; full citizenship was not available to paupers. Political tensions arose from issues of taxation, public spending, regulation of business, and market supervision, as well as the limits of corporate autonomy.