This is a hard question to answer as it necessitates a full-length biography, so bear in mind this is just skimming the surface.

Nicholas II is a complex historical personage that that intermingled a personal affability and a striking political incompetence. Most cinematic depictions of Nicholas II emphasize his role as a devoted father and husband and this was not that far off from the mark, although they also omit his well-known antisemitism. He was by most accounts a decent family man and his personal household very much resembled that of Queen Victoria. The royal family in tsarist iconography emphasized the almost bourgeois quality of Nicholas II's family. For example, Nicholas II was the first tsar to actually share a sleeping bed with his wife. Nicholas II even humored his wife's patronage of the monk Rasputin, a man the tsar never really trusted or liked.

However, the family man Nicholas II was singularly ill-suited to his position as an absolute monarch. He fused two dangerous elements into his rule: he held a deep conviction in the sacred inviolability of the position of tsar and consistently overestimated his own political acumen. These tendencies came to the fore as Russia felt increasing pressures from modernization and industrialization. Russian cities grew tremendously at the turn of the century and the ancient Romanov monarchy and its absolutist state appeared increasingly archaic for many Russians. The tsars ordinarily relied on a cadre of able servitors to run the state and Nicholas II inherited his father's able servant Sergei Witte and later had Pyotr Stolypin to help him. But Nicholas II never really trusted these men and was ill at ease with being a tsar in an age of mass politics. The basic goal of the tsars in the nineteenth century was to modernize the economy while preventing any meaningful political reform. The result was political discontent compounded itself since the tsarist state was fostering the very demographic changes that undermined the traditionalism that was the bedrock of Romanov absolutism.

The monarchy itself was shaken to its core during the Revolution of 1905, which occurred during the disastrous Russo-Japanese War, which was another blunder of Nicholas II. The Romanovs weathered the 1905 Revolution, but needed to accept a limited constitution and a legislature called the Duma. However, the 1905 Revolution resulted in a peculiar political situation that some historians have described as "constitutional absolutism." Stolypin tried to act like Bismarck, that is as a White Revolutionary who would reform society while using nationalism to strengthen the monarchy against democracy. Nicholas II though was a check to Stolypin's ambitious plan. Unlike Bismarck's pliant Wilhelm I, Nicholas II was unwilling to cede political power to his prime minister. The result was that after the 1905 Revolution, the Russian state limped along, apparently intact and with some strengths, but with a number of unresolved political and social tensions.

The First World War was in many respects the absolute worst thing for the Romanovs. The economic stresses of the wartime economy, coupled with the losses of some of the empire's prosperous Western regions, exacerbated preexisting tensions between the state and Russia's working classes. The war also unleashed greater ethnic stresses within the multiethnic empire, which were simmering prior to 1914, but war brought them to a boil. Nicholas II, in a blunder characteristic of much of his rule, tried to take a more hands on approach to the handling of the war. Although he often deferred to military professionals, his rather public assumption of supreme command further damaged his battered prestige. When revolution came in early 1917, Nicholas II abdicated after it was clear that the monarchy could not cling to power as it did in 1905. The Russian Provisional Government tried to re-stabilize Russia, but were unable to control the increasingly radicalized Russian street. This led to a second Russian revolution in 1917, which brought the Bolsheviks to power. Nicholas II and his family became something of a political football during the resulting Russian civil war. The remnants of the Provisional Government sought to exile him to further distance themselves from the previous regime while traditionalist and anti-Bolshevik White forces wanted to use the Romanovs as a rallying point to retake the country.The Bolsheviks ended up in control physical control over the tsar and his family in the Urals town of Yekaterinburg. Some in Moscow wanted to put Nicholas II on trial as a symbolic propaganda victory, but such an undertaking would have been difficult. Eventually, the proximity of a local White army led the local Bolsheviks to forge documents claiming that Nicholas II was plotting with France to restore the monarchy as a pretext to execute the whole family.

Sources

Hosking, Geoffrey A. Russia: People and Empire, 1552-1917. Cambridge, Mass: Harvard University Press, 1997.

Weeks, Theodore R. Across the Revolutionary Divide: Russia and the USSR, 1861-1945. Chichester, West Sussex: Wiley-Blackwell, 2011.

Wortman, Richard S. Scenarios of Power: Myth and Ceremony in Russian Monarchy. Vol. 2, Vol. 2. Princeton, N.J.: Princeton Univ. Press, 2000.