1658
The rebuilding of the salt town of Salzgitter begins with the restoration of the Vöppstedt church as a church for the dead and the windmill on Windmühlenberg. The completely ruined town gates are provisionally repaired.

1691
Dukes Rudolf August and Anton Ulrich elevate the free secular Steterburg monastery to a free secular, noble virgin monastery.

1756 - 1763
Seven Years' War. Duke Carl I of Brunswick-Lüneburg is the brother-in-law of Frederick the Great and his ally. In 1757, 1760 and 1761, the French invade the area and plunder it.

1758
The Schwicheldt estate in Flachstöckheim serves as headquarters for the famous Prince Henry of Prussia. At his instigation, French prisoners of war create a rococo garden at the estate, which is transformed into an English garden at the beginning of the 19th century.

1761
The French "Codenvian Corps" stands before Salzgitter. There is a tremendous inflation. The office has to pay the French 20000 thalers in damages. Young and old people are forced into military service.

1803
The ecclesiastical principalities in Germany are secularized. Hildesheim Abbey falls to Prussia. Ringelheim Abbey is abolished. King Friedrich Wilhelm III hands it over to his field marshal Count von der Schulenburg-Kehnert, who leaves it to his daughter, Princess von Hatzfeld-Drachenberg, as a dowry.

1806 - 1815
The Napoleonic Wars. After the Battle of Jena and Auerstädt, parts of the defeated Prussian army flee north along what is now the Federal Road 248. The French colonel la Chaise takes possession of Salzgitter and becomes its commander. He has the Vöppstedt Church of the Dead cleared of all equipment and turns it into a military prison. It served as such until 1815. From that day on, it was left to decay.

1808
The Kingdom of Westphalia is created by Napoleon's claim to power. The former diocese of Hildesheim and the Duchy of Brunswick were incorporated into it, bringing it under foreign rule for the first time since its creation. It effectively lasted until 1813.

1813
After the Battle of Leipzig, George III, King of England and Hanover, finally mobilizes his subjects as well as the inhabitants of the former diocese of Hildesheim, which had fallen to Prussia in 1803. They are assembled and trained in "Landwehr battalions". One of these battalions in red skirts was garrisoned in Salzgitter. It raises its men in the villages of the later district of Goslar. In 1815, this battalion took part in the Battle of Waterloo. Around 1910, Kaiser Wilhelm II transfers the tradition of the Salzgitter battalion to the 1st Hanoverian Infantry Regiment "Princess Albrecht of Prussia" in Hanover.

1815 - 1906
The Salzgitter musicians, the Klesmer, go out into the world. Due to the cessation of spinning and weaving throughout southern Hanover, the cottagers and craftsmen of this area are in need. They turn to music and use it to conquer European countries, North and South America and Australia. Inhabitants from 86 towns and villages in southern Hanover and Brunswick travel the world with the "Salzgitter Musicians".

1847
In this year of famine, Count Adolf von der Decken has the famous Ringelheim Park laid out as an emergency measure.

1848
In the revolutionary year of 1848, residents' militias are formed in all the towns in the region, with the intention of storming Liebenburg Castle in Salzgitter and Ohlendorf in order to free prisoners. As a result, the bailiwick of Salzgitter and its villages are subjected to military punishment.

1856
The first railroad in the urban area, from Börßum to Kreiensen, is completed. In the same year, the council and administration of the town of Salzgitter sell their town hall on the market square (now the Ratskeller in Salzgitter-Bad) to an innkeeper.

1861
The keep of Lichtenberg Castle, which is still 21 meters high, is taken down.

1866
In the so-called "German Unification War", the King of Hanover joins Austria and the German southern states. The Prussians therefore occupy the kingdom, which is finally awarded to them in the Peace of Prague. As a result, the former Hanoverian lands and towns become Prussian. The former bishopric now forms the administrative district of Hildesheim. The Duchy of Brunswick had remained neutral in this war and therefore remained intact.

1868
Emil Langen from Solingen (1824 - 1870) establishes the "Aktiengesellschaft Eisenwerk Salzgitter" with four blast furnaces, coking plants and foundries at the Gittertor in Salzgitter. In 1870, he was killed in a blast furnace explosion.

1874
The ironworks falls victim to the Vienna bank crash.

1872
The first borehole for potash salts in the local area is drilled in the gypsum quarry near Thiede.

1885
The Thiederhall trade union near Thiede sinks the first shaft and the Derneburg-Lichtenberg-Salder-Braunschweig railroad is built.

1892 - 1893
Restoration of the Lichtenberg ruins and construction of the new tower.

1896
The "Schlüssel" trade union christens a shaft for potash on the Greif near Salzgitter, which at its time is the deepest salt shaft in the world with a 1075-meter level. The joyful news that the long-sought potash deposit worth mining had finally been found at the 1075-meter level on 27.3.1905 was replaced by the terrible news that the mine had been sunk by a leach collapse.

1911
The shaft of the Friedrichsrode potash plant is sunk at Worthla near Flachstöckheim, and the new bathhouse is built in Salzgitter-Bad.

1920
Duke Ernst August von Braunschweig sells the salt works to "Saline Liebenhalle GmbH Hannover". The saltworks fall into disrepair and individual buildings are put up for auction in 1934.

1922
Anton Raky, a drilling entrepreneur known far beyond Germany, moves the headquarters of his company from Erkelenz to Salzgitter. He constructs halls and buildings on Windmühlenberg, which become the nucleus of the Reichswerke in 1937.

1924
The Thiederhall potash works near Thiede and Friedrichsrode near Flachstöckheim are shut down on the basis of the "Closure of Potash Mines" Act of September 24, 1919.

1937
Foundation of the Reichswerke (15.7.).

1939 - 1945
The Second World War with 1,111 air raids. While the smelter is frequently attacked, the housing estates are relatively spared.