After World War I and the subsequent Greek-Turkish War from 1919 to 1922 and finally peace in the form of the Lausanne treaty, the Chemins de fer Orientaux (CO) ended up having a network straddling Turkey and Greece. This created operational difficulties, each country having now its own set of rules &amp; regulations, currencies, languages, ... In order to resolve this situation, the CO decided to split itself into two companies: one for the Greek part, one for the Turkish part of the railway.