Many of the key sources about Emperor Peter III were from Empress Catherine's memoirs - of which she wrote various versions, and those of her friend Princess Dashkova.

As Peter III's usurper, of course Catherine was not going to be full of positive things to say about him.

Before we go further, it's worthy of note that just like Catherine, who'd come from the minor principality of Anhalt-Zerbst in modern-day Germany, Peter III was essentially an foreign monarch.

Peter III grew up in Holstein-Gottorp, in modern-day Denmark and Northern Germany, and was in effect transplanted to Russia by his aunt Elizabeth of Russia (Peter the Great's daughter who had herself come to the throne in a coup curiously like the one Catherine the Great would carry out). Naturally, Peter III's more European ideas of rule - less despotic and enlightened than the style of rule in Russia, would naturally be in his psyche. Before and while the Tsar, Peter III was de jure the Duke of Holstein-Gottorp.

So, onto Peter III's reign.

Perhaps the strongest sign of Peter III's lack of popularity (which doesn't necessarily mean he was a buffoon) was that after his brief six-month rule, nobody appeared to show much interest in bringing him back (not that they had much opportunity, considering Peter III's untimely death less than two weeks later.)

Not a total fool

However, Peter III also proved to be more thoughtful and progressive than the petty, ill-tempered buffoon in Catherine's memoirs seems to suggest. During his six-month reign, Peter III introduced numerous progressive reforms (some of which were later reversed by Catherine).

These reforms - almost certainly influenced by Peter III's idol, Frederick the Great - included:

• Making it illegal for landowners to kill their serfs
• Abolishing the secret police
• Proclaiming religious freedom
• “Emancipating” the nobility from obligatory state service - including military service

Evidence of buffoonery

Stronger, more objective evidence of Peter III's buffoonery was his seeming infatuation with Prussia and Frederick the Great - which ultimately served to prop up an almost defeated foe.

After successful Austro-Russian campaigns against Prussia under the reign of his aunt, Tsarina Elisabeth, as soon as Peter III became tsar he immediately ended hostilities against Prussia- meaning Russia's previous struggle had been in vain. Snatching defeat from the jaws of very likely victory would be known as the Miracle of the House of Brandenberg - an all-but defeated Frederick the Great being able to recover from a seemingly mortal blow.

To put into context the importance of Peter III's Prussian u-turn, close to two hundred years later in 1945, Hitler in his Berlin bunker - brandishing a newspaper report on the death of US President Franklin Roosevelt - would refer to this historic event, in the vain hope the fortunes of Nazi Germany would turn in a similar manner.

You could argue that Peter III's actions here in saving Prussia would ultimately prove ruinous 150 years later, when the First World War began.

Foolhardy

Furthermore, Peter III also sought to invade Denmark to recover the territory of Schleswig for his native Duchy of Holstein, land lost some decades earlier. Other than for Peter III's personal pride, it is apparent that conquering Denmark would do nothing for Russia. In the event, Peter III was deposed before the invasion could begin.

Historian W. Bruce Lincoln writes:

In his [Peter III's] foreign policy... there is no way to escape the conclusion that Peter III was extremely unwise, even foolhardy.

Closer to court, Peter's further blunders included:

• Referring to his Russian bodyguard units as "janissaries," (the Ottoman Empire's equivalent to the Roman Praetorian Guard) and ordering them to don Prussian-style uniforms and march in the Prussian style
• Replacing his closest bodyguards with his own Holsteiners
• Insisting everyone who held honourary rank in the Russian army (including senior officials and statesman) take part in parades (no matter how old, fat or infirm they were)
• Annexing church estates (serfs and all), which made him unpopular with the church (proclaiming religious freedom in a church which long enjoyed a monopoly can't have helped win over the clergy, either).

Thus, by alienating his own guards and courtiers, Peter III created a rod for his own back - which put Catherine in a position to oust him and seize the throne for herself.

With, of course, the support of alienated courtiers and guards.

Peter III's mocked janissaries, at it turned out, were exactly that - kingmakers. Peter III was the second-to-last tsar deposed in a palace coup - the last being his and Catherine's son, Paul I, some four decades later, who resembled Peter III in appearance and character.

Scandalous

Losing the throne to his wife, who had not one drop of Russian blood, might seem scandalous to us now.

But it was somewhat less scandalous at the time - considering that Peter the Great had four decades earlier put in a place a rather chaotic system where the ruler chooses their successor (in Peter the Great's case, his successor was his wife, Empress Catherine I, who had little interest or talent at ruling Russia).

Thus, this arbitrary aspect of succession already been fraught with intrigue, the widespread (but not total) acceptance of Catherine the Great as successor didn't seem as illegitimate at the time.

Also, Peter III's dethroning, during the decades-long era of palace coups in Russia that resulted after the death of Peter the Great, did in effect ensure something of a meritocracy, or least survival of the fittest, on the throne.

The (mostly) clearer succession and transition the Romanovs would enjoy from 1801-1917 would bring stability - the cost being stagnation.

Suggested sources:

• Memoirs of the Empress Catherine II - available on Gutenberg
• Romanovs: Autocrats of all the Russias - W Bruce Lincoln
• Inside the Third Reich - Albert Speer