Königsberg (Kaliningrad) & Riga

Königsberg

Königsberg (Kaliningrad) commented by Braun

“Die Fürstliche Hauptt Statt Koningssbergk in Preussen”

“Königsberg in Prussia is a most noble and famous city, which was founded in the year 1254 by the Teutonic Knights. Alongside their artisan activities, the citizens engaged first and foremost in maritime trade. They thereby dealt in grain, solid and liquid pitch, which the Germans call resin, as well as salt, flax, hemp, wax, wood and also in a great deal of honey and mead; this is a sweet drink that is made from honey and comes from Livonia.”

CARTOUCHE: Königsberg, a Prussian or Borussian city on the sea, beautiful residence of the prince.

Taschen on Königsberg (Kaliningrad)

Königsberg’s location on the Pregel, shortly before it reaches the Vistula Lagoon on the Baltic Sea, is made especially clear in this combination of elevation and bird’s-eye view directly from the south. The river separates the town of Kneiphof on the island from the Old Town (above) and the town of Löbenicht (in the west). With the founding of the Old Town in 1254 by the Teutonic Knights, the two other towns also sprang up, but remained independent until 1724. Within Königsberg proper, the Old Town church (Alt Steter Pfarkirch) can be seen on the left and, beside it to the right, the palace of the Teutonic Knights (Schlos) with its tall tower (Schlos thurn). In 1457 Königsberg became the primary residence of the Grand Master of the Teutonic Knights and in 1525 was incorporated into the Duchy of Prussia. On the Island of Kneiphof lie Königsberg cathedral and on the right the Albertina University (Collegium), founded in 1544 by Albert I, Duke of Brandenburg. Königsberg was completely destroyed in 1944/45. In 1946 Königsberg passed to Russia and was renamed Kaliningrad, and became the capital of the eponymous Russian exclave situated between Lithuania and Poland.

The Seven Bridges of Königsberg is a historically notable problem in mathematics. Its negative resolution by Leonard Euler in 1736 laid the foundations of graph theory and prefigured the idea of topology. Königsberg  was set on both sides of the Pregel, and included two large islands (Kneiphof and Lomse) which were connected to each other, or to the two mainland portions of the city, by seven bridges. The problem was to devise a walk through the city that would cross each of those bridges once and only once. By way of specifying the logical task unambiguously, solutions involving either

1. reaching an island or mainland bank other than via one of the bridges, or
2. accessing any bridge without crossing to its other end

are explicitly unacceptable.

Euler proved that the problem has no solution. The difficulty he faced was the development of a suitable technique of analysis, and of subsequent tests that established this assertion with mathematical rigor.

The view by Braun and Hiogenberg only shows six of the seven bridges: the seventh bridge is hidden behind the local people on the foreground.