From 1887, the Sud Express ran from Paris to the Spanish border, where passengers would transfer to the Spanish and Portuguese Sudstock for the rest of their journey to Madrid and Lisbon.
The original concept for the SUD express was conceived by the founder of the CIWL, Georges Nagelmakers. His plan was to introduce a service running from St. Petersburg to Madrid and Lisbon via Berlin and Paris. In order for this idea to have worked, the bogies of the sleepers would have to be changed at both the Russian and Spanish borders as both of these countries had a different track gauge to the rest of Europe.
The sleeping cars were originally 6 wheeled, but were upgraded in the early 1900's to wagon-saloon cars, offering a higher standard of travel. By the mid 1920's the Sud, in France, was a day train, usually consisting of 5 Pullman cars alongside 2 fourgons. The Spanish and Portuguese trains were made up of broad-gauge CIWL sleepers and diners.
After World War 2 the Sud's Pullman content was reduced to two coaches when the train was reinstated in 1947. This was later reduced again in 1955 to only one Pullman and a diner, the rest of the train consisting of ordinary SNCF coaches.
It was one of the two last trains to feature Pullman stock, the other being the Rome-Milan R30 express.