The Lea Valley lines are two commuter lines and two branches in north-east London, so named because they run along the Lower Lea Valley of the River Lea. They were part of the Great Eastern Railway, now part of the Anglia Route of Network Rail. On 31 May 2015, services between London Liverpool Street to Chingford, Cheshunt and Enfield Town were transferred to London Overground; services from London Liverpool Street and Stratford via Tottenham Hale to Hertford East and Bishops Stortford remain with Greater Anglia. Services operated by London Overground are now fully operated by new-built Class 710 rolling stock, replacing older Class 315 and Class 317 stock inherited from Greater Anglia. History The first section was opened by the Eastern Counties Railway (ECR) on 20 June 1839 from the London end at Devonshire Street to Romford, extended on 1 July 1840 to Bishopsgate (London end) and Brentwood. The Northern and Eastern Railway (N&ER) opened its first section from that line at Stratford to Broxbourne on 15 September 1840, and to Harlow in 1841; though it remained a separate entity, its line was leased to the ECR from 1 January 1844. A branch from Broxbourne to Hertford opened in 1843. Enfield was reached on 1 March 1849 by the single-track Enfield Town branch from the N&ER at Angel Road via Lower Edmonton. The ECR was incorporated into the Great Eastern Railway (GER) in 1862. A shorter route to Edmonton was provided by the GER in 1872, from Bethnal Green via Hackney Downs and Stoke Newington, which opened on 27 May; the section via Seven Sisters and Lower Edmonton, at a new high-level station provided adjacent to the old low-level station, opened on 22 July. The line from there to Enfield was doubled at the same time. The old line between Angel Road and Lower Edmonton was closed to passenger trains in 1939, except for occasional diversionary traffic including the period in the 1950s when the rest of the local network was being electrified under the Eastern Region; the line closed completely in 1964 and the track was removed soon after. Another branch, the Chingford branch line, went from Lea Bridge to Walthamstow, Shern Hall Street, in 1870, extended southwards to Hackney Downs in 1872 and northwards to Chingford in 1873. The final section linked Lower Edmonton on the Enfield branch via Churchbury (later Southbury) with the Broxbourne line at Cheshunt,