A brutal murder and a desperate plea: What really happened between the Windsors and the Romanovs.

There's a storyline in season five of The Crown which has fascinated everyone who has watched the latest instalment of the Netflix series. 

In episode six, titled Ipatiev House, there was a flashback to the sticky history between the British Royal Family and their Russian cousins in the early 20th century.

During this era, the House of Windsor and Buckingham Palace was headed by the late Queen Elizabeth's grandfather King George V and his wife Queen Mary.

Queen Victoria, King George V's grandmother, is often referred to as "the grandmother of Europe" given that lots of her children and grandkids married into royal families across the globe. As a result, King George V's first cousin was none other than Tsar Nicholas II of Russia.

Although Nicholas II and George V were first cousins, they could easily have passed as twins.

Nicholas II and George V in 1913. Image: Getty.

The two cousins were relatively close throughout the years; even though relations between their two countries weren't great. Their families would often meet up, including in 1909, which was heavily covered by the press at the time. 

But the 1909 meeting wasn't purely just a family occasion - it was also designed to solidify an alliance, given Tsar Nicholas II (then the head of Russia) thought of England as Russia's 'sworn enemy'. It was only after years of "diplomatic courting" that Russia signed an agreement allying itself with England.

By 1917, things were not going well for Nicholas II and his family.

World War I had broken out, with Europe in disarray. And by 1917, the Russian Revolution was taking place, leading to Tsar Nicholas II and his wife Alexandra being overthrown from power. 

It led to Nicholas II and his whole family - the Romanovs - going into hiding for fear of their lives being cut short at the hands of Bolshevik revolutionaries. At the time, the Romanovs weren't exactly held in high esteem with the Russian public, and there was growing frustration shown towards this 300-year imperial dynasty.

While in hiding, the Romanovs reached out to George V, and his fellow Windsors, to see if they would help them find a place of safety - namely requesting refuge in England. 

It's at this point where The Crown starts to depict what happened next.

An aide told King George V the British government "is willing to send a ship to bring the Romanovs to safety here in England. The Prime Minister does not wish to do so without your support."

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George V and his wife Queen Mary exchanged worried glances, because there were consequences with either option they decided on. 

If they let the Romanovs find refuge in England, that would likely further strain relations between the UK and Russia. It would also pull the English public out of favour with the royals, as public opinion on Russia was at an all-time low.

The second option - to not let the Romanovs into England - would likely result in their eventual deaths or capture by those now in power in Russia. But it would ensure the British royal family would not get stuck in a sticky PR nightmare by cutting ties with the 'problematic' and unpopular Romanovs.

George V goes with the second option, reportedly not expecting it would result in the death of his cousin.

By July 1918, things weren't looking good for the Romanovs. On the night of July 17, Nicholas II, his wife and their five kids - daughters Olga, Tatiana, Maria, and Anastasia, and son Alexis - were informed by a soldier they were being moved to "a safer place". At that moment, they were being housed in Ipatiev House, located deep within the Russian countryside.

"It's cousin George! I told you he wouldn't let us down. Cousin George has saved us!" Nicholas II said according to history reports, waking up his family and telling them to start packing to leave.

The Romanovs were then led into Ipatiev House's basement, for a final family photo in Russia, the soldiers claimed. As the Romanovs smiled for the photo, more and more soldiers - Bolshevik revolutionaries to be exact - begin firing bullets at the family, killing them with guns and stabbing them with bayonets. The entire family was brutally murdered. 

The British royal family, as it turns out, had refused to help the Romanovs with safe passage to the United Kingdom.

The Windsors and the Romanovs together in 1909. Image: Getty.

Following on from the brutal murders, the revolutionaries took the bodies of the Romanov family, and dumped them in a makeshift grave in the Russian countryside, and doused the deceased in sulphuric acid and gasoline, before lighting them on fire. It was done in a bid to ensure their remains could never be identified in the future.

But the Bolsheviks evidently didn't do as good a job as they had hoped.

In 1979, amateur historians discovered the remains of Nicholas, Alexandra, and three of their five children - Olga, Tatiana, and Anastasia. In 1991, the Romanov gravesite was excavated, and the bodies were allowed to be exhumed following approval from the newly formed Russian Federation government. 

The Russians then requested the DNA of Prince Philip, Queen Elizabeth's husband, to confirm if the remains found were actually the Romanovs. Because interestingly, as the European royal families have inter-married so often, Prince Philip was Nicholas II's wife Alexandra's grandnephew.

Prince Philip was reportedly very keen to be a part of the process, and through his DNA, the remains were confirmed to be the Romanovs.

Nicholas II and his family were then given a formal state funeral after the Soviet Union's collapse. In 2007, the partial remains of two skeletons believed to be the remaining Romanov children, Alexei and Maria, were found.

The whole case, particularly the DNA examinations done in the '90s, helped accelerate the development of new forensic testing methods. 

And it also helped solve one of the greatest historical crime mysteries of the 20th century.

Feature Image: Getty.