Upon his return home, Broz was unable to gain employment as a metalworker in Kumrovec, so he and his wife moved briefly to Zagreb, where he worked as a waiter and took part in a waiter's strike. He also joined the Communist Party of Yugoslavia (CPY).
By 1920, Luciano had met many future Mafia leaders, including Vito Genovese and Frank Costello, his longtime friend and future business partner through the Five Points Gang. That same year, Lower Manhattan gang boss Joe Masseria recruited Luciano as one of his gunmen. Around that same time, Luciano and his close associates started working for gambler Arnold "The Brain" Rothstein, who immediately saw the potential windfall from Prohibition and educated Luciano on running bootleg alcohol as a business.
In January 1920, as Pesmen-Rubin's revenue declined after Christmas, Disney and Iwerks were laid off. They started their own business, the short-lived Iwerks-Disney Commercial Artists. Failing to attract many customers, Disney and Iwerks agreed that Disney should leave temporarily to earn money at the Kansas City Film Ad Company, run by A. V. Cauger; the following month Iwerks, who was not able to run their business alone, also joined.
During Himmler's second year at university, Himmler redoubled his attempts to pursue a military career. Although he was not successful, he was able to extend his involvement in the paramilitary scene in Munich. It was at this time that he first met Ernst Röhm, an early member of the Nazi Party and co-founder of the Sturmabteilung ("Storm Battalion"; SA). Himmler admired Röhm because he was a decorated combat soldier, and at his suggestion, Himmler joined his antisemitic nationalist group, the Bund Reichskriegsflagge (Imperial War Flag Society).
In early 1920, Romanian troops departed Hungary. They took with them resources including foodstuffs, mineral ores and transportation and factory equipment and also discovered historic bells of Romanian churches in Budapest taken by the Hungarians from Austro-Hungarian Army, which had not been melted then.
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 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17, 1920, the Eighteenth Amendment to the U.S. Constitution took effect and Prohibition lasted until the amendment was repealed in 1933.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.
From 1920, Eisenhower served under a succession of talented generals – Fox Conner, John J. Pershing, Douglas MacArthur, and George Marshall. He first became executive officer to General Conner in the Panama Canal Zone, where, joined by Mamie, he served until 1924.
The British increased the use of force; reluctant to deploy the regular British Army into the country in greater numbers, they set up two paramilitary police units to aid the RIC. The Black and Tans were seven thousand strong, mainly ex-British soldiers demobilized after World War I. Deployed to Ireland in March 1920, most came from English and Scottish cities. While officially they were part of the RIC, in reality, they were a paramilitary force.
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.
The Irish Republican Police (IRP) was founded between April and June 1920, under the authority of Dáil Éireann and the former IRA Chief of Staff Cathal Brugha to replace the RIC and to enforce the ruling of the Dáil Courts, set up under the Irish Republic.
In early April 1920, 400 abandoned RIC barracks were burned to the ground to prevent them being used again, along with almost one hundred income tax offices. The RIC withdrew from much of the countryside, leaving it in the hands of the IRA.
In Belgium in 1920, Andre Gratia and Sara Dath observed a fungal contamination in one of their Staphylococcus aureus cultures that was inhibiting the growth of the bacterium. They identified the fungus as a species of Penicillium and presented their observations as a paper, but it received little attention. An Institut Pasteur scientist, Costa Rican Clodomiro Picado Twight, similarly recorded the antibiotic effect of Penicillium in 1923.
Though widely traveled, Edward was racially prejudiced against foreigners and many of the Empire's subjects, believing that whites were inherently superior. In 1920, on a visit to Australia, he wrote of Indigenous Australians: "they are the most revolting form of living creatures I've ever seen!! They are the lowest known form of human beings & are the nearest thing to monkeys."
In May 1920, Dublin dockers refused to handle any war matériel and were soon joined by the Irish Transport and General Workers' Union, who banned railway drivers from carrying members of the British forces. Blackleg train drivers were brought over from England, after drivers refused to carry British troops. The strike badly hampered British troop movements until December 1920, when it was called off.
In June–July 1920, assizes failed all across the south and west of Ireland; trials by jury could not be held because jurors would not attend. The collapse of the court system demoralised the RIC and many police resigned or retired.
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.
In July 1920, another quasi-military police body, the Auxiliaries, consisting of 2,215 former British army officers, arrived in Ireland. The Auxiliary Division had a reputation just as bad as the Tans for their mistreatment of the civilian population but tended to be more effective and more willing to take on the IRA. The policy of reprisals, which involved public denunciation or denial and private approval, was famously satirised by Lord Hugh Cecil when he said: "It seems to be agreed that there is no such thing as reprisals but they are having a good effect".
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.
Kawamata hoped to pass the exams of First Upper School, which was under the direction of the Tokyo Imperial University. He succeeded in the exam the same year and entered the Humanities Faculty as an English major in July 1920. A young Kawabata, by this time, was enamored by the works of another Asian Nobel laureate, Rabindranath Tagore.
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.
In 1904, John Ambrose Fleming invented the thermionic diode, the first kind of vacuum tube. This used a hot cathode that caused an electric current to flow in a vacuum. This idea was quickly applied to X-ray tubes, and hence heated-cathode X-ray tubes, called "Coolidge tubes", completely replaced the troublesome cold cathode tubes by about 1920.
The partition of the Ottoman Empire was finalized under the terms of the 1920 Treaty of Sèvres. This treaty, as designed in the Conference of London, allowed the Sultan to retain his position and title. The status of Anatolia was problematic given the occupied forces.
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 August 1920, UNIA organized the First International Conference of the Negro Peoples in Harlem. This parade was attended by Gabriel Johnson, the Mayor of Monrovia in Liberia. As part of it, an estimated 25,000 people assembled in Madison Square Gardens.
On hearing of their dilemma, couturière Coco Chanel invited Stravinsky and his family to reside at her new mansion "Bel Respiro" in the Paris suburb of Garches until they could find a more suitable residence; they arrived during the second week of September. At the same time, Chanel also guaranteed the new (December 1920) Ballets Russes production of Stravinsky's The Rite of Spring with an anonymous gift to Diaghilev, said to have been 300,000 francs.
Poland and Lithuania both regained their independence but soon became immersed in territorial disputes. During the Polish–Soviet War, Lithuania signed the Moscow Peace Treaty with the Soviet Union that laid out Lithuania's frontiers. On 7 October 1920, the League negotiated the Suwałki Agreement establishing a cease-fire and a demarcation line between the two nations.
Violence escalated steadily from that summer and sharply after November 1920 until July 1921. (It was in this period that a mutiny broke out among the Connaught Rangers, stationed in India. Two were killed whilst trying to storm an armory and one was later executed).
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.
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.
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.
In December 1920, Quốc (Ho) became a representative to the Congress of Tours of the Socialist Party of France, voted for the Third International and was a founding member of the French Communist Party. Taking a position in the Colonial Committee of the party, he tried to draw his comrades' attention towards people in French colonies including Indochina, but his efforts were often unsuccessful.
In the Government of Ireland Act 1920 (enacted in December 1920), the British government attempted to solve the conflict by creating two Home Rule parliaments in Ireland: Northern Ireland and Southern Ireland. While Dáil Éireann ignored this, deeming the Irish Republic to be already in existence, Unionists in the north-east accepted it and prepared to form their own government.
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.
1920 Haiyuan earthquake occurred on December 16 in Haiyuan County, Ningxia Province, Republic of China. It was also called the 1920 Gansu earthquake because Ningxia was a part of Gansu Province when the earthquake occurred. The earthquake hit at 19:05:53 Gansu-Sichuan time (12:05:53 UTC), reportedly 7.8 on the Richter magnitude scale, and was followed by a series of aftershocks for three years. Total casualties were reported as 200,000 in a summary published by the United States Geological Survey, and 235,502 according to the Catalog of Damaging Earthquakes in the World (through 2008) maintained by the International Institute of Seismology and Earthquake Engineering.