The oldest section of the line opened on 9 June 1856 from Olten to Aarburg-Oftringen as part of a line built by the Swiss Central Railway (German: Schweizerische Centralbahn) between Aarau, Olten, Aarburg and Emmenbrücke (near Lucerne).

Only 15 days later, on 16 June 1857, this was followed by the extension of the line from Herzogenbuchsee to Burgdorf and Zollikofen to the edge of the city of Bern at Wylerfeld.

The line from Olten to Aarburg-Oftringen was limited to 40 km/h and therefore was an obstacle to the operation of express trains between Bern and Zürich.

[3] The line is designed for a maximum speed of 140 km/h and although it is only 5.5 kilometres (3.4 mi) long it saved 3–4 minutes between Zürich and Bern.

It is almost 52 kilometres (32 mi) long, with one branch to Solothurn and the Jura foot railway line to Neuchâtel, Yverdon and Geneva.

The line has a maximum speed of 200 kilometers per hour and reduced the travel time between major Swiss hubs of Bern, Basel and Zürich to under an hour allowing the regular interval timetable (German: Taktfahrplan) to be put into effect, where both express and stopping trains on all lines arrive and leave on the hour at Bern and Zürich stations, allowing a great number of convenient connections.

[4] On 30 April 2004, the last piece of rail was put into place at the Bern-Solothurn canton border at Inkwil on the connection to Solothurn.