There are 4 photo galleries for Greece, one covering motive power types, one for all OSE standard gauge lines, one for the former Thessaly Railway lines and the other covering the Piraeus-Athens-Peloponnese metre gauge system

The title page of the 1962
SEK railway timetable

By European standards railways came late to Greece with the first section of line between Athens & Piraeus not being opened until 1869 and it was into the early years of the 20th century before there were any significant additions with the completion of the standard gauge line from Athens to Larissa. The extension of this to complete the main to Thessaloniki did not open to traffic until 1918. The decline of the Ottoman Empire greatly enlarged the borders of Greece during the era of railway construction for prior to 1912 northern Thessaly and the areas of Macedonia & Thrace that formally became part of Greece following the Treaty of Sevres in 1920, were administered by Turkey. All lines in these areas either being operated by The Oriental Railway - (CO) Chemin de Fer Orientaux or under a concession granted by Turkey.
Hellenic State Railways (SEK) took over most standard gauge lines in Greece from 1st June 1920. The major exception being the CO route from Alexandropolis to Svilengrad on the Bulgarian border which the Turkish company continued to operate until 29th June 1929 when it was vested in a new company, the Chemin de Fer Franco-Hellinique. The latter finally went bankrupt in 1952 and was purchased by the SEK on 7th March 1954. Thessaly Railways were nationalised in in May 1955 and its line from Larissa to Volos was converted to standard gauge operation in 1960. In later years its line from Paleofarlos to Kalambaka was converted to standard gauge operation in 2001 whilst the remaining metre gauge section between Volos & Paleofarlos was closed in 1999, leaving only part of the 60cm gauge Pelion Railway east of Volos operating to this day. The final act of the consolidation of all Greek Railways under SEK control took place in September 1962 when all the remaining metre gauge lines, apart from those of Thessaly, that had previously been merged with the Piraeus-Athens-Peloponnese Railway were themselves merged with the SEK.