The years 1825-1918 were bloody and traumatic, a period when four tsars tried - and failed - to deal with the growing pressure for constitutional reform and revolution. In 1861, millions of enslaved serfs were freed by the Tsar-Liberator, Alexander II. But Alexander paid the ultimate penalty for opening the Pandora's box of reform when he was later blown up by terrorists on the streets of St Petersburg. Elsewhere, there was repression, denial, war and - in the case of the last tsar, Nicholas II - a fatalistic belief in the power of God, with Nicholas's faith in the notorious holy man Rasputin being a major part in his undoing. Lucy Worsley also details the chilling murder of Nicholas and his family in 1918, and asks whether all of this horror have been avoided.

In 1914, Russia entered World War I in response to Austria-Hungary's declaration of war on Russia's ally Serbia. This was fought across multiple fronts while isolated from its allies. The Battle of Tannenberg, where the entire Russian Second Army was annihilated, cast an ominous shadow over the empire's future. The already-existing public distrust of the regime was deepened by the rising costs of the war and rumours of corruption. World War I takes Nicholas to the front. Back home, outrage grows over high casualties and Alexandra and Rasputin's political intrigues.

Nicholas felt enormous pressure to continue the dynasty and expand the empire. He saw his opportunity in the Far East. This brought him into conflict with a rising power, Japan. Russia's disastrous war against Japan prompts civil unrest. The birth of Prince Alexei is incredibly important. He's the long-awaited son that they had hoped so much for. But when Alexei is diagnosed with haemophilia, Siberian mystic Rasputin steps in. He's very good at realizing when something is open that will enable him to increase his power and wealth. The pressure of keeping the secret of Alexei's illness affects the political decisions that Nicky and Alix made for the rest of their reign.

The Romanovs retreat into a bubble of luxury while the czar's forces brutally suppress protests by a starving populace. Rasputin's influence grows, never mind the rumors and scandals. Many people believe Prime minister Peter Stolypin is the last hope of the Romanov Dynasty as reformer-in-chief. He is horrified by the rise of Rasputin. The fight between Stolypin and Rasputin is a battle for influence over Nicholas II. But Stolypin is shot in the Kiev Opera in 1911.

Rasputin is gone, but Nicholas II continues his catastrophic policies in war and at home. When Nicholas goes back to military headquarters, he is in fact leaving control of government, exactly when Russia needed to be held together by its Czar. The war by this time is deeply unpopular. It's not only unpopular, it's also arguably the engine that's causing enormous economic crisis, that's causing general unrest. Deprivation pushes the population from unrest to revolution.