It runs generally north through Cheshunt, Broxbourne, Harlow, Bishop's Stortford and Audley End (near Saffron Walden) to Cambridge, with branches between serving Stratford, Hertford and Stansted Airport.

It was this railway company opened the section from Bishops Stortford to Cambridge as part of its extension to Ely and Brandon in 1845.

In 1952 the branch from Elsenham to Thaxted (known as the "Gin & Toffee Line") closed to passengers, and goods services were withdrawn a year later.

Electrification to Chingford included the Stratford – Lea Bridge – Hall Farm Junction section (although this was never completed), and the line from Liverpool Street to Broxbourne via Seven Sisters and the Southbury Loop was electrified.

The route via Tottenham Hale was still operated by diesel traction, the British Rail Class 125 'Lea Valley' DMUs.

In 1991, a single-track branch line to Stansted Airport was opened, and services to London Liverpool Street commenced.

In May 2015, services from Liverpool Street to Chingford, Enfield Town and Cheshunt via Seven Sisters transferred to London Overground, along with a new station opening at Lea Bridge.

Services from Liverpool Street to Cambridge, Hertford East and Stansted Airport are operated by Greater Anglia.

[4] Line-side train monitoring equipment includes hot axle box detectors (HABD) on the up main south of Newport (39 miles 48 chains from Liverpool Street) and on the down main north of Shepreth Branch Junction (53 miles 10 chains).

Following nationalisation in 1948 British Railways introduced the Britannia 4-6-2 class on some main line services until succeeded by diesels in the late 1950s.

Intermediate stations from Tottenham Hale will transfer to Crossrail 2 releasing capacity on the mainline for additional trains.

[11] In August 2019, it was announced that funding had been approved for four-tracking and related platform construction work between Tottenham Hale and Meridian Water to enable up to 8 trains per hour to make local stops in this section at peak times.