What happened 1920AD in undefined

The League of Nations was the first worldwide international organization whose principle mission to maintain world peace. It was founded on 10 January 1920 following the Paris Peace Conference that ended World War I, and the headquarters was in Geneva, Switzerland.

On 10 January 1920, the League of Nations formally came into being when the Covenant of the League of Nations, ratified by 42 nations in 1919, took effect.

On January 17, 1920, the Eighteenth Amendment to the U.S. Constitution took effect and Prohibition lasted until the amendment was repealed in 1933. The amendment prohibited the manufacture, sale, and transportation of alcoholic beverages. Demand for alcohol naturally continued, the resulting black market for alcoholic beverages providing criminals with an additional source of income.

In March 1920, Tomás Mac Curtain, the Sinn Féin Lord Mayor of Cork, was shot dead in front of his wife at his home, by men with blackened faces who were seen returning to the local police barracks. The jury at the inquest into his death returned a verdict of wilful murder against David Lloyd George (the British Prime Minister) and District Inspector Swanzy, among others. Swanzy was later tracked down and killed in Lisburn, County Antrim. This pattern of killings and reprisals escalated in the second half of 1920 and in 1921.

Hitler was discharged from the army on 31 March 1920 and began working full-time for the NSDAP (National Socialist German Workers Party).

Karol Józef Wojtyła was born in the Polish town of Wadowice. He was the youngest of three children born to Karol Wojtyła (1879–1941), an ethnic Pole, and Emilia Kaczorowska (1884–1929), whose mother's maiden surname was Scholz.

On 8 June 1920, the entire family left Morges for the last time, and moved to the fishing village of Carantec in Brittany for the summer while also seeking a new home in Paris.

The first cycle of attacks and reprisals broke out in the summer of 1920. On 19 June a week of inter-sectarian rioting and sniping started in Derry, resulting in 18 deaths.

Under the Treaty of Versailles, Germany lost around 13 percent of its home territory and all its overseas possessions, limits were placed on the size and and capability of the country's armed forces.

On 17 July 1920, a British Colonel Gerald Smyth was assassinated by the IRA in the County Club in Cork city in response to a speech that was made to police officers of Listowel who had refused orders to move into the more urban areas, in which he stated "you may make mistakes occasionally, and innocent persons may be shot, but that cannot be helped.

On 21 July 1920, partly in response to the killing of Smyth and partly because of competition over jobs due to the high unemployment rate, loyalists marched on the Harland and Wolff shipyards in Belfast and forced over 7,000 Catholic and left-wing Protestant workers from their jobs. Sectarian rioting broke out in response in Belfast and Derry, resulting in about 40 deaths and many Catholics and Protestants being expelled from their homes.

Article 230 of the Treaty of Sèvres required the Ottoman Empire to hand over to the Allied Powers the persons responsible for the massacres committed during the war on 1 August 1914.

On 9 August 1920, the British Parliament passed the Restoration of Order in Ireland Act. It replaced the trial by jury by courts-martial by regulation for those areas where IRA activity was prevalent.

On 22 August 1920, RIC Detective Swanzy was shot dead by Cork IRA men while leaving a church in Lisburn, County Antrim. Swanzy had been blamed by an inquest jury for the killing of Cork Mayor Tomás Mac Curtain.

In the autumn of 1920 he and his pregnant wife returned to his homeland, first by train to Narva, by ship to Stettin, then by train to Vienna, where they arrived on 20 September.

Alvaro Obregón was elected president in October 1920, the first of a string of revolutionary generals.

Between 1 November 1920 and 7 June 1921 twenty-four men were executed by the British.

Then, on 21 November 1920, there was a day of dramatic bloodshed in Dublin. In the early morning, Collins' Squad attempted to wipe out the leading British intelligence operatives in the capital. The Squad shot 19 people, killing 14 and wounding 5. These consisted of British Army officers, police officers and civilians. The dead included members of the Cairo Gang and a courts-martial officer, and were killed at different places around Dublin.

About 300 people had been killed by late 1920, but the conflict escalated in November. On Bloody Sunday in Dublin, 21 November 1920, fourteen British intelligence operatives were assassinated in the morning; then in the afternoon the RIC opened fire on a crowd at a Gaelic football match, killing fourteen civilians and wounding 65. A week later, seventeen Auxiliaries were killed by the IRA in the Kilmichael Ambush in County Cork.

On 28 November 1920, only a week after Bloody Sunday in Dublin, the west Cork unit of the IRA, under Tom Barry, ambushed a patrol of Auxiliaries at Kilmichael in County Cork, killing all but one of the 18-man patrol.

On 10 December 1920, martial law was proclaimed in Counties Cork, Kerry, Limerick and Tipperary in Munster; in January 1921 martial law was extended to the rest of Munster in Counties Clare and Waterford, as well as Counties Kilkenny and Wexford in Leinster.

On 11 December, the centre of Cork City was burnt out by the Black and Tans, who then shot at firefighters trying to tackle the blaze, in reprisal for an IRA ambush in the city on 11 December 1920 which killed one Auxiliary and wounded eleven.