The history of Koenigsberg from its foundation till the beginning of the XX century is the history of the town behind walls. The walls of the Royal Castle initiated the town and defended knights of the German Order. Walls of the medieval towns which were built around a castle calmed and protected citizens. After all, defensive banks encircled all the territory of the future Koenigsberg.

A single fortification, the First defensive belt encircled the three cities, their suburbs and far-away territories with the 15-meter ring, was built in 1626-1634. Vulnerability of Koenigsberg during the Polish-Swedish war was the reason to build it.

New political situation after the Seven-year war (1756-1763) defined the other menace for Prussia – Russia could expand from the East. At that time the First defensive belt was in poor condition and the Prussian estate asked the king for modernization.

The Second defensive belt was built on the place of the old one except the northern and southern boundaries – they were moved outside. Location of the gates remained unchanged for they were connected with the roads from the town. Construction began in 1843 and almost finished in 1859. Ernst Ludwig von Aster (1778-1855), lieutenant general of engineer troops, controlled projecting and General von Breeze (1787-1878) controlled building.

The Second defensive belt consisted of 12 bastions, 3 ravelins, 7 spoil banks and 2 defensive fortresses surrounded by water moat. Only 10 gates of the city served as entrances and passages through defensive lines. All of them were made of bricks and equipped with defensive walls and lifting bridges.

City gates as open visual dominants were architecturally decorated in fashionable eclectic style of English Neo-Gothic, the Tudor style. Frederick August Schtuler (1800-1865) and William Ludwig Schturmer (app. 1812-1864), an architect and a sculptor respectively, were to decorate the facades of the most important city gates. Koenigsberg got a fortress of the first category after the Second defensive belt had been finished.

A paradox of a grand, long-lasting and expensive building was that before the works were finished the fortress had lost its purpose to defend citizens. A rapid development of artillery made walls and gates useless. As a result citadels were moved far to the suburbs. The fortress ring was step by step passed to civil authorities and till the 1930-s it had been transformed into a park zone. At the same time a part of banks, bastions and gates were removed because they hampered the development of infrastructure.

A complex of the last fortifications – the Fort belt – was built in 1872-1890. It consisted of 12 separate forts with space between them. After it had been built Koenigsberg acquired the biggest defensive belt in Germany.