However, this meant that, in order to reach the City, the NLR's trains had to take a fairly circuitous route, and so the company decided to build its own central terminus.

c. cxcvi) was passed giving permission to the NLR to build an extension from its main line through Hackney to a site at Old Broad Street.

The majority of the route was built on a viaduct from Dalston, with a triangular junction allowing access to the main line in both directions.

The route was electrified in 1916 using the 600 V DC third and fourth rail system, with the purchase of new electric rolling stock.

The route was earmarked for closure under the Beeching Axe in 1963, but remained open due to local pressure.