It was the mystery that captured the imagination of the world, as a Russian Imperial dynasty was ruthlessly executed before details of their disappearance obfuscated for decades.

In 2018, the true story of how the Duke of Edinburgh helped piece together the murders of Tsar Nicholas II and his family was told by the Science Museum in an exhibition detailing how his DNA provided the key.

The Duke, who offered a blood sample to experts attempting to identify bodies found in unmarked graves in 1993, provided a match with the Tsarina and her daughters, related through the maternal line, proving once and for all their fate.

The research by that team, known in detail only to scientists until recently, was put on display for the first time, with graphs of the Tsar’s own DNA exhibited alongside details of the Duke’s contribution of five cubic centimetres of blood.

The Duke is the grand-nephew of the Tsarina, with her older sister Victoria Mountbatten his maternal grandmother.

He was invited to assist the investigation into her murder by Dr Peter Gill and his team at the Forensic Science Service, who used mitochondrial DNA analysis to determine they have proved "virtually beyond doubt" that bones found in a grave in Yekaterinburg in July 1991 were those of the Romanovs.