De Mayerling a Sarajevo (Max Ophuls, 1940)

In the late 1800's, Franz Ferdinand, heir to the Austro-Hungarian empire, falls for Sophie Chotek, a Czech countess. He's already a problem to the Crown because of his political ideas; this love affair with someone not of royal blood breeches protocol. The Crown allows the union only after the couple agrees to a morganatic marriage. The emperor further neutralizes Franz by making him inspector general of the army, sending him afield for months at a time. In June of 1914, fearing for his safety, Sophie seeks permission to accompany Franz to Sarajevo; protocol dictates that no army troops attend Franz while she is present. An assassin strikes. Their deaths spark World War I.