The major events that compose the history of railways in Greece are:
1869
Inauguration of railway services between Thision - Piraeus.
1882
The stock company "Athens Railways - Piraeus - Peloponnese" (SPAP) is founded, based in Athens.
1884
Official inauguration of the Thessalian Railway and first train journey from Volos to Larissa.
1890
The Northwestern Greece Railway Company (SBDE) is founded and begins operating in the Messolonghi - Agrinio line.
1920
The "Greek State Railways" (SEK) is founded as a public corporation with a view to consolidating and restructuring all hitherto operated regional railways of the Greek State; it is completed in 1965.
1970
The "Hellenic Railways Organization" (OSE) is founded aiming at the unified organization, operation and development of railway transport.
1997
The operation of the first electrified railway line between Thessaloniki – Idomeni is inaugurated.
2007
The EDISY SA and TRAINOSE SA companies are created, to mark the newly stated separation of Infrastructure and Utilization. In 2008, infrastructure development is completely separated from the Group and directly assigned to the Greek State.
2010
Absorption of the former subsidiary EDISY SA by OSE SA is completed and the immediate implementation of the new institutional framework starts, aiming at the restructuring and modernization of OSE SA.
2011
-Streamlining the Organization's costs and human resources.
-The balance sheet (EBITDA) of OSE SA turns positive for the first time in years.
-Radical restructuring of the organizational structure.
2012
-The balance sheet of OSE SA (EBITDA) remains positive for a second consecutive year.
-Implementation of the new organizational structure.
The following legislation acts are introduced:
- Separation of the rolling stock maintenance industry and its absorption by the newly established "Greek Railway Rolling Stock Maintenance Company" (EESSTY SA)
- Transfer of GAIAOSE SA shares to the Greek State
2013
- Transfer of GAIAOSE shares to the Greek State is completed (Government Gazette 759 / vol. B '/ 03.04.2013).
-Separation of the Rolling Stock Maintenance Industry from OSE SA and its integration to EESSTY SA are completed (Government Gazette 1993 / 08.14.2013).
-Transfer of Rolling Stock Maintenance Industry human resources to EESSTY SA
-Development of Quality Management System and Environmental Management System according to International Standards ISO 9001 and 14001 respectively.
-OSE SA receives confirmation of Management Competency Type A & B - "Arrangements for the confirmation of Management Competency of beneficiaries for the period 2007 - 2013".
-The Company consolidates the above systems (Quality Management System, Environmental Management System and Management Competency System) into a Single Integrated Management System.