During a trip to the United States in 1868, the young Belgian engineer Georges Nagelmackers travelled on Pullman trains and experienced their famous sleeping cars. But while some American trains were more technologically advanced than their European counterparts, they were still very uncomfortable.

Known as “the King of Trains and the Train of Kings,” the Orient Express paired innovation with elegance. Its cabins featured the most modern amenities of their day—central heating, hot water and gas lighting. They included an upholstered interior, where passengers found impeccably outfitted beds and robes sporting the company crest. Only the finest materials were used: silk sheets, marble bath fixtures, crystal goblets and silver cutlery. During the day, twenty cabins were converted into lounges.

In its heyday, many celebrities travelled in the luxurious berths of the Orient Express, including King Ferdinand of Bulgaria, Russian novelist Leo Tolstoy, American actress Marlene Dietrich, and Russian ballet impresario Sergei Diaghilev. Other well-known passengers included adventurers such as Lawrence of Arabia and spies like the famous Mata-Hari.

When he filmed Christie’s well-known mystery in 1974, US director Sidney Lumet brought some of the world’s greatest actors aboard, including Lauren Bacall, Ingrid Bergman, Sean Connery and Anthony Perkins. A new version with an equally prestigious cast was released in 2017, with Kenneth Branagh directing and playing the lead role as the famous detective Hercule Poirot. To date some 15 films have been inspired by Agatha Christie’s classic whodunnit.