Up until the 19th century, history was mainly about how rulers and military commanders won or lost battles due to personal strengths and weaknesses. The genre is still thriving, and gradually more structural and generalised approaches to the theme have appeared. One interesting study is a wide-ranging survey from 2004 in which the psychologists Steven L. Rubenzer and Thomas R. Faschingbauer compared the personalities, characteristics and leadership decisions of every American president since the formation of the republic in 1776.

The duo asked historians, writers and journalists to evaluate the leadership of the presidents. The outcome of the almost 600-question-long survey was not straightforward. While the sources were very heterogeneous, respondents could nevertheless recognise eight leadership types: dominators, introverts, ‘good guys’, innocents, actors, preservationists, philosophers and extroverts. The highest scores for good leadership, according to this comparison, went to Franklin D Roosevelt and John F. Kennedy, extroverts who were not only clever but also master manipulators.

Do these claims have any relevance when we focus on the leadership and statecraft of Finland’s most renowned public figure, Gustaf Mannerheim? Yes and no. Certain features in decision-making are universal, others are historically and geographically specific. Despite being born in 1867 in the north-eastern periphery of Europe, in the Grand Duchy of Finland, at that time one of the poorest countries on the continent, during his career Mannerheim would take part in, and in some cases be solely responsible for, decisions that would have a formative impact not only on Finnish but also European history.

After a three-decade-long career in the Russian army, Mannerheim returned to Finland in late 1917, which, due to the increasing chaos in the Russian Empire after the Bolshevik coup, had declared its independence. When the Russian Revolution of January 1918 spread to Finland, he was appointed commander-in-chief of his country’s counter-revolutionary army and led it to victory in May 1918. After a comfortable private life during the interwar period, he was called back to the same position in late autumn of 1939, when Finland was dragged into the Second World War, staying in post until ending his career as president of Finland from 1944–6.

Mannerheim’s biologically inherited gifts were favourable but not exceptional. With his six-foot height, resilient health and attractive looks, he certainly caught attention. As the offspring of one of Finland’s leading noble families, his background was also privileged, but his early educational records were less convincing. As a teenager he was relegated for bad behaviour both from his grammar school and the Finnish Cadet Corps. Through his family’s ties to the Russian imperial elite, he got a new chance at the Nicholas Cavalry School in St Petersburg, which gave his motivation a needed boost, and his career took a positive turn.

His adolescent shortcomings might have been a psychological reaction to his father’s bankruptcy and scandalous escape with a mistress to Paris. On the other hand, his six siblings seemed to have carried the social shame much more ably, and they all got decent civilian educations. A more plausible explanation could be that the young Mannerheim, due to his wild nature and often foolhardy bravery, simply needed more hardship and discipline to get on the right track.

Mannerheim passed the exam at Nicholas Cavalry School with a high score and, in 1889, started his first military appointment in the small Polish town of Kalisz. This only intensified his ambition to be admitted to the prestigious Chevalier Guards in St Petersburg. This goal, once again thanks to his family’s close links to the imperial court, soon bore fruit. During his first years in this regiment, who were the life guards of the Russian empress, he was introduced to court life and married a Russian noblewoman with a substantial fortune, Anastasia Arapova, who gave birth to two daughters. He also made a name for himself in prestigious equestrian competitions. The marriage brought him wealth and influence, but ended a decade later in divorce due to his adultery.

Mannerheim’s professional advances were, at that stage, unimpressive. He failed the entrance examination to the Russian military academy, and his promotions remained minimal until 1904, when he enrolled as a volunteer in the Russo-Japanese War. The war was lost, but the skilful horseman showed his ability as a frontline officer and was sent on a two-year espionage expedition through Central Asia – an extremely demanding task on horseback – which he completed so successfully that his military career took off.

When the First World War broke out, Mannerheim had reached the rank of major-general, and during the war he rose to commander of a cavalry corps before the revolutionary chaos in the summer of 1917 began to disintegrate the Imperial Army.

All these turning points would transform the flamboyant life-guard officer into a resilient commander with a realistic understanding of great power politics. He was thus well equipped when, in January 1918, he was appointed commander-in-chief of the troops of the newborn state of Finland, now in a state of revolution due to the country’s rocky transition to independence. The Finnish revolutionaries were strongly encouraged by the Russian Bolsheviks to win power and acquired weaponry from Russian soldiers left in Finland.

In March 1918, after the Bolshevik government had been forced to sign the Treaty of Brest-Litovsk with Germany – in which Lenin promised to stay aloof from the Finnish conflict – the war tipped in favour of Mannerheim’s White Army. The treaty also resulted in the Whites receiving decisive support from the German army; within three months the Finnish revolution was crushed. Mannerheim, however, was not at all happy to be working with his former enemies and resigned. He was convinced Germany would lose the war, and when that happened he was called back to function as regent in the wake of the resignation of Frederick Charles of Hesse, brother-in-law of German emperor Wilhelm II – a position he held until the summer of 1919.

During that short era, he advocated energetically for Finnish involvement on the counter-revolutionary side in the Russian Civil War. This awoke suspicions that he was less interested in Finnish independence than in the restoration of former Russian rule. After having signed the republican constitution of Finland, he stood as a candidate in the presidential election, but in large part due to these misgivings, he lost and retreated to a comfortable gentleman’s life on money raised by his devoted supporters.

His shortcomings in domestic politics between 1918 and 1919 convinced Mannerheim to stay aloof from parliamentary intrigues. But when tensions in great power politics in the 1930s grew sharper, his expertise and networks became more appreciated by the Finnish political elite than before. As chairman of the National Defence Committee, Mannerheim warned European governments repeatedly of the growing threats of a new war. He had maintained his contacts with leading European military and diplomatic actors, and claimed the only way for Finland to avoid becoming a battlefield was a military alliance with Sweden, which could calm down invasion plans by the Soviet Union and Germany.

The Swedish government was not prepared to bind its destiny to the risky borderland. Finland was thus thrown again into a world war, and Mannerheim was called to function once more as the commander-in-chief of the Finnish Army. Due to his age – he was 72 in 1939 – Mannerheim’s style of military leadership was in many ways out of date, but his geopolitical understanding and diplomatic experiences compensated for most of these shortcomings. When the Second World War ended in 1945, Finland was the only country in Eastern Europe that had avoided occupation and maintained its independence as well as its democratic institutions.

During this period, a crucial impact on Mannerheim’s military leadership was his trustful cooperation with Risto Ryti, Finnish prime minister during the Winter War – a three-and-a-half-month battle against Soviet invaders in 1939 – and president during a second Soviet war, known as the Continuation War, between 1941 and 1944. They were both Anglophiles, but after the Winter War each came to the conclusion that Finland’s only way to survive was through a military alliance with Germany, since Stalin was not prepared to leave Finland untouched.

The decisive moment came in late summer 1940, when Soviet pressure on Finland increased and Hitler secretly began to plan an invasion of the Soviet Union. Hitler was well-informed of the Soviet stress on Finland and offered its leadership first weaponry and goods, then diplomatic support, and finally, in December 1940, a military alliance. Could Mannerheim and Ryti have declined these offers? In principle yes, but in practice not. The Stalin and Hitler pact from 1939 was still in force. Even if their secret protocol, in which Finland was defined in the Soviet sphere of interest, was not known about by the Finnish leadership, it was easy to interpret Stalin’s intentions concerning Finland, not least after the Baltic states had been brutally incorporated into the Soviet Union.

All realistic alternatives had by then been thoroughly checked and ruled out. A Finno-Swedish alliance was bluntly denied by Moscow and Berlin. British military support was not an option after the Wehrmacht occupied Denmark and Norway. As so often before and thereafter, the Finnish leaders were forced to play the weak cards they held – in this case, they had to swiftly decide what great power to join before their country once again became dragged into a military conflict.

In that specific situation, an alliance with Hitler’s Germany was the only safe choice. If the German invitation had been declined, Finland would certainly have been occupied either by the Wehrmacht or the Red Army and would have lost any chance of manoeuvring through the clash between the two dictatorships with its independence intact. Instead, due to this skilful balancing act, Finland was able to cut its ties to Germany in September 1944 and sign the Armistice Treaty with the Allied Forces, which became the Paris Peace Treaty of 1947.

The German support for Finland had remained substantial throughout the Second World War, but an official alliance treaty was never signed. President Ryti could thus claim that Finland fought its own defensive battle to maintain its reputation among Western countries. Despite this, he and seven of his cabinet were brought to trial for war responsibility. The accused denied any responsibility for the alliance, but received jail sentences in February 1946. Ryti was given ten years, his seven officials shorter terms. The sentences were less harsh than those imposed on the guilty during the Nuremberg and Tokyo trials, and were widely understood as unfair, due to the difficult circumstances in which the politicians had taken their decision. But in many ways the sentences stigmatised their legacy.

Mannerheim’s fate was luckier. He had consciously avoided specific declarations about the nature of cooperation with Germany, and one month before the alliance ended he had finally been elected president – which in practice gave him immunity against any charges. Directly after the sentences were handed down to the politicians in March 1946, he resigned as president and spent most of his remaining life focusing on working on his memoirs.

In them, Mannerheim followed tightly the defence arguments put forward by the accused politicians. He played down the importance of German military support for Finland in 1941–4, and described his own position in the decision-making as subordinate to President Ryti and his war cabinet. Those claims were clearly not honest. The alliance with Germany had been crucial for the survival of Finnish independence, and Mannerheim’s geopolitical views had strongly informed Finnish strategies throughout the war.

The truth about the Finno-German alliance was not politically convenient to reveal when the crimes of the Nazi regime became public and Finland’s relationship with its former enemy, the Soviet Union, needed to be improved. In fact, it took a couple of decades before Finnish historians began to uncover the full extent of the alliance, and many Finnish citizens would stick much longer to the memory of a separate war.

Once this more critical picture of Finland’s role in both world wars began to unfold, it would reflect on Mannerheim’s legacy. Among many Finnish socialists, Mannerheim had, since the crushed revolution of 1918, been remembered as ‘the white butcher’, and as the Finno-German alliance was scrutinised more closely he was even accused by some of being Hitler’s lackey. His reputation has experienced a veritable rollercoaster ride over the years, but gradually a calmer and more diversified picture of him has taken shape, which offers space for considering the different dimensions of his leadership.

Returning to the eight leadership profiles characterised by Rubenzer and Faschingbauer, it is safe to claim that Mannerheim had a lot in common with the extroverts Franklin D. Roosevelt and John F. Kennedy. During his career in Russia, he learnt how to perform in public and built up an aura of heroic motives. He lacked the moral scruples to hide his own ambitions and strategic calculations, which might arouse condemnation but is in fact a quality required by every politician and decision-maker with any longevity.

Had he, in January 1918, told the Finnish government that he saw himself fighting the Reds primarily for Russia’s former rulers, he would not have been appointed. Had he, after the Second World War, admitted to being crucially responsible for Finland joining the German attack against the Soviet Union in the summer of 1941, he would have been accused of cowardice – or worse, considering President Ryti and seven government colleagues received jail sentences for the alliance with Germany.

Yet the consequences of these two hidden agendas were in the end favourable to both Finland and Mannerheim. He understood the military conflict between the Whites and Reds in Finland as part of the broader arenas of the Russian Revolution and the First World War, and he had no illusions about German motives for supporting the Finnish Whites. Thus he maintained his distanced attitude towards the Germans and could, after their capitulation, be called back to government to repair Finland’s damage in relation to the victorious Western powers.

The same geopolitical perspective was also typical of Mannerheim’s leadership during the next world war. As emphasised earlier, his decision to join the German offensive in the summer of 1941 was certainly not taken without hesitation, but it paid off. Finland managed to avoid a Soviet invasion, then cut the alliance with Germany, and finally secured its independence. Even if these were unintended chain reactions in the context of the larger war arena, things could easily have gone gravely wrong for Finland had it not been for Mannerheim’s leadership.