Around 50000 BC.
Palaeolithic people hunt reindeer in the Salzgitter region and catch rhinoceros and mammoth in pitfall traps. They make simple tools from wood, bone and flint. They make way for the approaching last ice age, which brings an arctic climate to the whole of Lower Saxony. Their summer camp near Lebenstedt is scientifically excavated in 1952.
Around 10000 BC.
The ice has receded. The plants arrive and with them the animals and humans. Their bones - mainly those of the mammoth - and tools washed into the Thied gypsum quarries in the "water year" 1817 are discovered during excavation work.
Around the year 0
Germanic tribes searching for iron ore discover the ores from Salzgitter, which they smelt and forge. A smelting furnace from this period - around 1 meter high - was excavated at Strauchholz in 1943. It dates from the end of the 3rd century.
772 - 804
Charlemagne's wars against the Saxons. They are forcibly converted to Christianity. As a result, the diocese of Hildesheim and the Duchy of Brunswick are formed in the northern Harz foreland.
Around 924
The castles of Steterburg and Kniestedt are built under King Henry I, Duke of Saxony, who is nicknamed "The Reeve". In 1956, a smelting furnace with lead slag and a short sword called a "Sachs", both dating back to the 10th century, were found in the area of Kniestedt Castle.
919 - 936
Henry I rules the German Empire as emperor. He was married to Mechthildis, Countess of Ringelheim. It was probably at this time that Ringelheim Abbey was founded as a "royal abbey". Mechthildis seems to have extinguished the dynasty of Ringelheim.
1003
The widow Hathwig of Count Altmann von Ölsburg, whose marriage had remained without male descendants, founded a nunnery on the Steterburg estate.
1125
First mention of a salt works at Gitter, in which Steterburg Monastery has a significant stake.
Around 1150
Henry the Lion, Duke of Saxony and Bavaria, builds a castle on the Lichtenberg to protect the trade route to Brunswick.
1151
The royal abbey of Ringelheim is abolished as an aristocratic convent, converted into a male (Benedictine) monastery in 1152 and placed under the episcopal see of Hildesheim.
1154
Gebhardshagen Castle is first mentioned in a document as "hus to dem Haghen".
1180
Emperor Frederick Barbarossa conquers Lichtenberg Castle after Henry the Lion is outlawed.
1205 - 1208
The Guelph castle falls into the hands of the Hohenstaufen counterparty, which protects the imperial city of Goslar against the Guelphs.
1272
The Sol spring near Salzgitter dries up despite all the pleas and technical efforts of the monks of the monastery.
1276
First mention of the Vöppstedt salt works.
1292
Bishop Siegfried II of Hildesheim (1279 - 1310) builds Lewerburg Castle, now called Liebenburg, on the Lewerberg as a counterweight to the Guelph castle of Lichtenberg. Attempts by the Lichtenberg garrison to prevent this construction by force of arms are unsuccessful.
Around 1350
The Vöppstedt salt farmers move their residence to the salt marsh, receive town rights and the right to protect the town with walls, ditches and ramparts. The new settlement is given the name "Solt to Gytere", today's "Salzgitter".
1370
The Lords of Kniestedt sell their property in Salzgitter to the Bishop's See in Hildesheim: Salzkoten, the jurisdiction to which they are entitled in the town and the interest from all salt estates operated in the town.
1393
The year of the "Last Honest Knight's Battle". Hans von Schwichelt from Flachstöckheim and Kurt von Steinberg defeat Duke Friedrich von Braunschweig near Beinum. However, they fall into an ambush set by 900 horsemen of the Elector of Saxony.
1406
(May 22) Bishop Johann von Hildesheim's men, Heinrich von Bortfeld and Burghard von Cramm, shoot up the walls of Gebhardshagen Castle and take it. The pledge holders, the duke's men Jan and Burchhard von Saldern, are ordered to rebuild the arsenal and the Red and Grey Towers.
1481 - 1486
The beer feud. Bishop Barthold von Hildesheim demands an extraordinary beer tax from his subjects in order to reduce the debts of the bishopric. He finds two powerful opponents: the knightly pledge holders of the collegiate castles and the towns. The town of Salzgitter does not join the alliance of towns. In 1485, it is besieged by citizens of Goslar and Brunswick. Among other things, St. Mary's Church on Marienplatz and St. Jacob's Church on Ostwall are destroyed.
1486
While the "wooden" Marienkirche was not rebuilt, work began on the new Jacobuskirche in 1486. It is surrounded by walls and a wide moat for future use.