Brandenburg) and the duke of Bavaria-Ingolstadt, the ruins and the forest belonging to the castle were purchased by the city (1427), resulting in the city's total sovereignty within its borders. Through these and other acquisitions the city accumulated considerable territory. The Hussite Wars, recurrence of the Black Death in 1437, and the First Margrave War led to a severe fall in population in the mid-15th century. At the beginning of the 16th century, siding with Albert IV, Duke of Bavaria-Munich, in the Landshut War of Succession led the city to gain substantial territory, resulting in lands of 25 sq mi (64.7 km), becoming one of the largest Imperial cities.
The cultural flowering of Nuremberg, in the 15th and 16th centuries, made it the centre of the German Renaissance. In 1525, Nuremberg accepted the Protestant Reformation, and in 1532, the religious Peace of Nuremberg, by which the Lutherans gained important concessions, was signed there. During the 1552 revolution against Charles V, Nuremberg tried to purchase its neutrality, but the city was attacked without a declaration of war and was forced into a disadvantageous peace. At the Peace of Augsburg, the possessions of the Protestants were confirmed by the Emperor, their religious privileges extended and their independence from the Bishop of Bamberg affirmed, while the 1520s' secularisation of the monasteries was also approved.
The state of affairs in the early 16th century, increased trade routes elsewhere and the ossification of the social hierarchy and legal structures contributed to the decline in trade. Frequent quartering of Imperial, Swedish and League soldiers, the financial costs of the war and the cessation of trade caused irreparable damage to the city and a near-halving of the population. In 1632, the city, occupied by the forces of Gustavus Adolphus of Sweden, was besieged by the army of Imperial general Albrecht von Wallenstein. The city declined after the war and recovered its
