▁Northern ▁He ights ▁lines . ▁ ▁Great ▁Northern ▁& ▁City ▁Railway ▁After ▁the ▁U ER L ▁and ▁the ▁Metropolitan ▁Railway ▁( MR ) ▁were ▁brought ▁under ▁public ▁control ▁in ▁the ▁form ▁of ▁the ▁London ▁Pass enger ▁Transport ▁Board ▁( L PT B ) ▁in ▁ 1 9 3 3 , ▁the ▁MR ' s ▁subs idi ary , ▁the ▁Great ▁Northern ▁& ▁City ▁Railway , ▁which ▁ran ▁from ▁Mo org ate ▁to ▁F ins bury ▁Park , ▁became ▁part ▁of ▁the ▁Under ground ▁as ▁the ▁Northern ▁City ▁Line . ▁In ▁prepar ation ▁for ▁the ▁Northern ▁He ights ▁Plan , ▁it ▁was ▁operated ▁as ▁part ▁of ▁the ▁Northern ▁line , ▁although ▁it ▁was ▁never ▁connected ▁to ▁it . ▁ ▁Northern ▁He ights ▁plan ▁ ▁See ▁Ed g ware , ▁High gate ▁and ▁London ▁Railway ▁for ▁a ▁detailed ▁history ▁of ▁the ▁company . ▁In ▁June ▁ 1 9 3 5 , ▁the ▁L PT B ▁announced ▁the ▁New ▁Works ▁Program me , ▁an ▁am bit ious ▁plan ▁to ▁expand ▁the ▁Under ground ▁network ▁which ▁included ▁the ▁integration ▁of ▁a ▁complex ▁of ▁existing ▁London ▁and ▁North ▁Eastern ▁Railway ▁( L NER ) ▁lines ▁north ▁of ▁High gate ▁through ▁the ▁Northern ▁He ights . ▁These ▁lines , ▁built ▁in ▁the ▁ 1 8 6 0 s ▁and ▁ 1 8 7 0 s ▁by ▁the ▁Ed g ware , ▁High gate ▁and ▁London ▁Railway ▁( E H & LR ) ▁and ▁its ▁success ors , ▁ran ▁from ▁F ins bury ▁Park ▁to ▁Ed g ware ▁via ▁High