The region was formed in at nationalisation in 1948, mostly out of the former Great Northern, Great Eastern and Great Central lines that were merged into the LNER in 1923. Of all the "Big Four" pre-nationalisation railway companies, the LNER was most in need of significant investment. In the immediate post-war period there was a need to rebuild the destroyed stations in London and along the busy East Coast Main Line and former Great Central Railway. Additionally, the LNER had begun a suburban electrification programme which the British Transport Commission was pledged to continue. It was partially for this reason that the former LNER in England was divided into Eastern and North Eastern regions to focus investment, unlike the other English and Welsh regions that wholly took over their resp