There are many historical inaccuracies in this film, but neither the filmmakers nor Robert K. Massie, upon whose book this title is based, can be held responsible for the inaccuracies in regard to characters and events. When Robert K. Massie initially researched materials for his book, the Soviet government was still in power in Russia, and would only authorize viewing of those "facts" that had been assumed by people and "approved" by the ruling government to be examined by researchers of the Romanov family. It was not until the Soviet government fell in 1991, that documents that had been secretly put away, and which were hidden from the public could be fully examined and researched.
For many years, it was believed that Prime Minister David Lloyd George's wartime coalition government would not allow the Romanovs to come to the UK after the first revolution in 1917. However, many years later it was confirmed that it was King George V who was against the idea, due to the possibility of unrest similar to the previous year's Easter Rising in Ireland. The King forced the government to withdraw its offer of asylum to the Romanovs, in an apparent abuse of his position as a constitutional monarch.
Arthur Zimmermann (Curd Jürgens), the German Foreign Secretary, was instrumental in trying to arm rebellions in Ireland and India during World War I, as well as offering a military alliance with Mexico, which caused the United States to enter the conflict.
The execution scene proved to be emotionally taxing for the four young actresses playing the Grand Duchesses (Ania Marson, Lynne Frederick, Candace Glendenning, Fiona Fullerton). The director noticed that the girls had gotten so "caught up in the story" and had drawn such a close bond with the each other, that they had felt like they where all a real family. During the actual filming of the execution scene, some of the girls broke down into tears and got hysterical on the set. In between takes they where taken backstage and given cups of tea in order to calm down before they returned to finish filming the dramatic and violent sequence.
Press reports at time of pre-production said that Rex Harrison and Vanessa Redgrave were to appear as the leads. However, a recent biography of Producer Sam Spiegel stated that paperwork (in an Israeli museum) belonging to Spiegel shows that he never offered them the leads.
Despite the massive box-office success and critical acclaim that Sam Spiegel had brought Columbia Pictures with On the Waterfront (1954), The Bridge on the River Kwai (1957), and Lawrence of Arabia (1962), the studio was unwilling to give Spiegel the budget he needed, due to a string of recent box-office failures, including The Chase (1966) and The Night of the Generals (1967).
It has been speculated that if Russia had focused on defeating Austro-Hungary in World War I the revolution could have been avoided. The Russians were forced to end a successful offensive against the Austrians in Galicia in order to attack German-held Silesia in September 1914.
A rare leading role for Michael Jayston in a theatrical film. Coincidentally, Alexander Knox, who appears in this film, also had a rare leading role in another Oscar-nominated historical biopic, Wilson (1944).