Count Udo of Katlenburg owned an estate on the bank of a brook, the Krummes Wasser (crooked water).

On the other side of this brook a market town developed at the end of the 12th century, mainly due to convenient access for traffic.

Einbeck was topographically extended and a town wall is mentioned that enclosed the market church St. Jacob and the stift St. Alexandri.

St Jacob was (and is) located in the center of the city around the 'old market', St. Alexandri was built only some hundred meters away.

Smaller villages as Oldendorf or Tiedexen were deserted and inhabitants moved inside the city walls.

Einbeck joined the Hanse in 1368 thus broadening the distribution area which now reached from Antwerp in the west to Riga in the east and from Stockholm in the north to Munich in the south.

Convicted of the crime, the arsonist, Heinrich Diek, was tortured and died while being publicly displayed in an iron cage.

Einbeck joined the Schmalkaldic League, a system of military defence of Lutheran princes and cities, which was a very costly exercise.

During the Thirty Years' War the city was occupied by enemy troops during 1632 and 1641 and some hundred houses destroyed.

As the neighbouring village Rotenkirchen developed into the administrative seat of the area, its sovereign was able to curb the autonomy of Einbeck.

After Prussia won the war against the Kingdom of Hannover in 1866, barracks for the Prussian Army were built, now the 'New Town Hall' and administrative building of the city council.

Beginning in 1890 the bicycle manufacturing and trading company of August Stukenbrok developed into the largest mail order business in Germany, although it later went into receivership during The Great Depression in 1931.

Einbeck was hit hard by the economic difficulties following the end of World War I, and from 1930 on, its citizens leaned toward non-democratic parties.

During the last free vote before Hitler took power, the National Socialists (NSDAP) had a share of 40.9% of the electorate in Einbeck.

Of the 58 Jewish citizens of Einbeck; 21 emigrated outside of Germany, 32 were killed or died of disease in concentration camps, three committed suicide, and five have not been able to be traced.

In 1946, the population of Einbeck doubled through the influx of displaced persons from the former Eastern territories of Germany, mainly from Silesia.

Residential housing expanded the city in an easterly direction, while industrial building grew to the south.

Einbeck is as of 2013[update] administratively a 'Medium Centre', which means it provides services like high school, hospital‚ notary public, local court, etc.

On October 19, 2011, the city council adopted a resolution to incorporate the neighbouring community of Kreiensen beginning January 1, 2013.

The export of beer was a very important business so that in the harbour city of Hamburg Einbeck had its own distribution center (and pub), called the Eimbeck'sches Haus.

[14] A worldwide business headquartered in Einbeck is KWS SAAT AG, listed in the German SDAX.

Every winter it hosts the international piano academy „Feuerwerk“, every spring young pianists from all Germany compete in the Einbecker Klavierfrühling competition.

Einbecker Morgenpost has its own staff and content for local news and takes international and national pages from "Hannoversche Allgemeine Zeitung".

There is an advertising paper for the Einbeck region called "Die Eule" distributed Wednesday and Sunday.

After their two-week stay the German students travel to places in the US such as Moab, Las Vegas and California.

A delegation of high school football (soccer) players, coaches and city officials visited Keene on July 1, 2010 and spent a week touring the city, playing exhibition games and watching the World Cup with the locals.

The larger railway station in Einbeck is Kreiensen, which provides in addition to the services mentioned above, train connections to the West (Holzminden, Altenbeken) and North East (Seesen, Goslar, Brunswick).