In this entry Brittanica attempts to explain away the Russian position in European history during the years of Russian supremacy(1814-1856) that were blunted when Britain, France and Sicily with the support of Austria and Prussia attacked Russia to protect the Ottoman Empire during the Crimean War that still echoes in the modern day.
Even though Britannica recognises Russian supremacy in Europe:
From the westward advance of its arms in the next two years of heavy fighting, Russia emerged as Europe’s greatest land power and the first among the continental victors over Napoleon. The immense prestige achieved in these campaigns was maintained until mid-century.
It underplays it:
During this period, Russian armies fought only against weaker enemies
Observe the language used:
But the Crimean War (1853–56) showed that this giant had feet of clay. The vast empire was unable to mobilize, equip, and transport enough troops to defeat the medium-size French and English forces under very mediocre command."
"Medium size", British storytelling is hilarious.
France mobilised over 300 thousand soldiers and Britain more than 100 thousand soldiers to help the Ottomans fight Russia in the 1850's, imagine the figures for the time. Sicily mobilised another 20 thousand, while Austria and Prussia(Germany) maintained a policy of "hostile neutrality against Russia", providing tacit and indirect support to the Ottomans.
Apparently a combined expeditionary force of about half a million soldiers in 1850 without counting the Ottomans was "medium-sized & mediocre".
Observe now British story-telling in action, take II.
To the upper classes in central Europe, Nicholas I was the stern defender of monarchical legitimacy; to democrats all over the world, he was “the gendarme of Europe” and the chief enemy of liberty.
Apparently, Nicholas I was the chief enemy of liberty in Europe despite the fact that he promoted liberalism in Switzerland, the Balkans and the Middle-east while his European enemies supported the Sultanate and the Monarchical status quo, despite the fact that the Crimean War took place to prevent the liberation & emancipation of the Christian people from the Ottoman Empire that was protected by Britain, France, Sicily, Austria & Prussia.
Europeans devoted half a million people to prevent the liberation of the Christian people in the Ottoman Empire and Brittanica claims that Nicholas the I was the enemy of liberty.
Hilarious propaganda that is quite shameless to be honest:
Count Capodistrias wrote:In 1809 Kapodistrias entered the service of Alexander I of Russia. His first important mission, in November 1813, was as unofficial Russian ambassador to Switzerland, with the task of helping disentangle the country from the French dominance imposed by Napoleon. He secured Swiss unity, independence and neutrality, which were formally guaranteed by the Great Powers, and actively facilitated the initiation of a new federal constitution for the 19 cantons that were the component states of Switzerland, with personal drafts.
Collaborating with Anthimos Gazis, in 1814 he founded in Vienna the "Philomuse Society", an educational organization promoting philhellenism, such as studies for the Greeks in Europe.
In the ensuing Congress of Vienna, 1815, as the Russian minister, he counterbalanced the paramount influence of the Austrian minister, Prince Metternich, and insisted on French state unity under a Bourbon monarch. He also obtained new international guarantees for the constitution and neutrality of Switzerland through an agreement among the Powers. After these brilliant diplomatic successes, Alexander I appointed Kapodistrias joint Foreign Minister of Russia (with Karl Robert Nesselrode).
In the course of his assignment as Foreign Minister of Russia, Kapodistrias's ideas came to represent a progressive alternative to Metternich's aims of Austrian domination of European affairs. Kapodistrias's liberal ideas of a new European order so threatened Metternich that he wrote in 1819:
Kapodistrias is not a bad man, but honestly speaking he is a complete and thorough fool, a perfect miracle of wrong-headedness...He lives in a world to which our minds are often transported by a bad nightmare.
— Metternich on Kapodistrias, 
Realising that Kapodistrias's progressive vision was antithetical to his own, Metternich then tried to undermine Kapodistrias's position in the Russian court. Although Metternich was not a decisive factor in Kapodistrias's leaving his post as Russian Foreign Minister, he nevertheless attempted to actively undermine Kapodistrias by rumour and innuendo. According to the French ambassador to Saint Petersburg, Metternich was a master of insinuation, and he attempted to neutralise Kapodistrias, viewing him as the only man capable of counterbalancing Metternich's own influence with the Russian court.
More than anyone else he possesses the art of devaluing opinions that are not his own; the most honourable life, the purest intentions are not sheltered from his insinuations. It is thus with profound ingenuity that he knew how to neutralize the influence of Count Capodistrias, the only one who could counterbalance his own.
— French ambassador on Metternich, 
Metternich, by default, succeeded in the short term, since Kapodistrias eventually left the Russian court on his own, but with time, Kapodistrias's ideas and policies for a new European order prevailed. He was always keenly interested in the cause of his native country, and in particular the state of affairs in the Seven Islands, which in a few decades' time had passed from French revolutionary influence to Russian protection and then to British rule. He always tried to attract his Emperor's attention to matters Greek.
As we saw earlier and Britannica confirmed, Russia was the preeminent European superpower from 1814(Congress of Vienna) until 1856(Crimean War).
Russia's Great Power status had been affirmed since 1721 under Peter the Great.
...take your common sense with you, and leave your prejudices behind...