His half-brother, Count József Károlyi (1884–1934), was the head of Fejér County, a member of parliament, and one of the prominent legitimist politicians of the Horthy era.

[citation needed] As an adult, "iron will, ambition, stubbornness and the security of his immense wealth drove him on his political career.

His mindset and character were shaped by external influences: including hatred towards the Habsburg dynasty, the traditional anti-German sentiment of his family, his foster father, the world-view of uncle Sándor Károlyi, his adoration of the 1848 revolution in Hungary, his idea of organizing peasants into farming cooperatives.

He wanted to make up for what he had missed as a teenager,[citation needed] throwing himself into the nightlife, with enthusiasm; he spent his time flagrantly, playing cards, having fun hunting.

When he was at home, his favourite pastimes were horse riding, polo and hunting, but he also enjoyed playing cards and chess[citation needed].

It was characteristic of the young Károlyi's recklessness that he sat on the frame of the one-seater airplane and clung to the iron bars, making his flight with legs hanging in the air.

Initially a supporter of the existing political and social system in Hungary, Károlyi gradually became more progressive, leaning to left-wing orientation during his career.

[citation needed] An important milestone in his confrontation with liberal conservatism was when, in June 1912, after the vote on the Defence Act, the parliamentary speaker István Tisza put an end to the opposition's protests with police violence.

[4] In 1914, at the time of the assassination of Archduke Franz Ferdinand, Károlyi was on his American tour, where he gave lectures at various universities with his friend Zsigmond Kunfi.

In particular, Károlyi demanded in 1915 that veterans should be granted the right to vote, which won so much popular support that it enraged Prime Minister, Count István Tisza.

In 1916 Károlyi broke off with his party, which had found his openly pro-Entente attitude to be too radical and dangerous for a war-time pacifist faction in parliament.

His only son, Adam Károlyi served in the Royal Air Force, who crashed due to a technical fault while testing an aircraft over the Isle of Wight in 1939.

One of Károlyi's first acts was to repudiate the compromise agreement on 31 October, effectively terminating the personal union with Austria and thus officially dissolving the Austro-Hungarian monarchy and state.

On the 1st of November, Károlyi's new government decided to recall all of the troops, who were conscripted from the territory of Kingdom of Hungary, which was a major blow for the Habsburg's armies on the fronts.

[citation needed] Only after Charles's withdrawal from government on 16 November 1918 made Károlyi proclaim the Hungarian Democratic Republic, with himself as provisional president.

However, he took up the case of pacifism in accordance with U.S. President Woodrow Wilson's Fourteen Points by ordering the unilateral self-disarmament of the Hungarian army, leaving the country defenseless at a time of particular vulnerability.

During their brief periods in power, Oszkár Jászi, hoped to create an "Eastern Switzerland" by persuading the non-Magyar peoples of Hungary to stay as part of the new Hungarian Republic.

[citation needed] The Belgrade Armistice was nonetheless seen as a victory for Károlyi, as it represented some degree of de facto recognition of his government on the part of the Allies.

Upon the National Council's seizure of power, Minister of Defence Béla Linder recalled all troops from the front and instructed all Hungarian units to lay down their arms.

Linder’s much maligned policy was very quickly reversed when Czechoslovak troops occupied several districts claimed by the Prague government in western Hungary on November 9th.

As a result, Linder resigned his post as Minister of Defence on November 9th and was replaced with Albert Bartha, who was now faced with the task of reorganizing and re-arming the Hungarian military.

With the economy on the verge of collapse as a result of the war, and with mass poverty and inflation, social reforms were introduced: unemployment benefit, tax arrears waivers, a ban on the employment of children under 14, wage increases, a token severance payment for demobilised soldiers, the introduction of an eight-hour working day and the extension of social security.

On 20 March 1919 the French presented the Vix Note ordering Hungarian troops further back into Hungary; it was widely assumed that the military lines would be the new frontiers.

For the time being, however, Károlyi managed to get the formerly moderate right-wing Hungarian newspaper, the Wiener Magyar Zeitung, to serve his cause; on 5 June 1920, one day after the signing of the Treaty of Trianon, Károlyi welcomed the economic blockade of Hungary, which was already in a difficult situation because of the White Terror, and the tone of the subsequent articles became even harsher:"Words will not win Horthy, he must be crushed by deeds.

Károlyi mainly tried to negotiate with the creators of the hostile Little Entente, Masaryk and Beneš, as well as with the Austrian Social Democratic Chancellor, Karl Renner.

[42][43] Eduard Benes sent Mihály Károlyi to Moscow as a Czechoslovak diplomat, as it seemed that the Soviet Red Army was on the verge of victory and would soon occupy Poland.

[41] Károlyi was accused of inciting rebel soldiers to assassinate the former prime minister (and his main political opponent) István Tisza at the beginning of the Aster Revolution.

The only certainty that emerged was that the threads of the plot did not originate from the National Council led by Mihály Károlyi, and the identities of the killers did not match those specified in the prosecutor's indictment based on the Hüttner testimony.

In the early years of the Horthy era, between 1921 and 1923, Károlyi was subjected to an officially sanctioned, contrived trial in which he was convicted of high treason and sentenced to the full confiscation of his assets.

The judgment held him guilty of high treason due to the unilateral disarmament of the large Honvéd army, which fatal decision had militarily enabled the Allies to dismember Hungary in the Treaty of Trianon.