Both Brunswick and Prussia put pressure on the Kingdom of Hanover to allow an east-west rail link.

It was only when he had participated in a trial run on the Brunswick line that he agreed in 1841 to a railway being built to his capital.

It would then connect from Brunswick to Wolfenbüttel by the line opened in 1843 and then branch east to Oschersleben and Magdeburg.

In 1853 the Hanoverian Southern Railway to Kassel was opened as the first line built from a branch in Hanover.

The Berlin–Lehrte line, which bypassed the junction at Brunswick, opened in 1871 and it captured the fast traffic to and from Berlin.

In the first decade of the 20th century fundamental changes were made to railway facilities in Hanover.

In 1906 the line between Tiergarten and Lehrte was moved south bypassing the old Misburg station.

A connecting curve now also runs from Hanover to Hamburg avoiding the need to reverse in Lehrte.

This was used for passenger trains between Hannover and Hamburg until the opening of the direct "Hare Railway" between Langenhagen (north of Hanover) and Celle in 1938 and its duplication and electrification in 1965.

In the 1973 Federal Transport Infrastructure Plan, the Dortmund–Hannover–Brunswick line was nominated as a railway to be upgraded for high speeds.

By the summer of 2008, the junction in Lehrte was changed again to allow freight trains from the Hannover freight bypass and the line from Celle to run towards Hildesheim and Brunswick, with the tracks of the high-speed line to Berlin running underneath.