and anti-Soviet Ukrainian troops attack the Red Army in Soviet Ukraine. April 26 – The Khorezm People's Soviet Republic is officially created by Soviet Russia, as the successor to the Khanate of Khiva. April 28 – The Azerbaijan Soviet Socialist Republic is officially created. May May 3 – A Bolshevik coup fails, in the Democratic Republic of Georgia. May 7 Polish–Soviet War: Polish troops occupy Kyiv. The government of the Ukrainian People's Republic returns to the city. Mexican Revolution: Venustiano Carranza leaves Mexico City in a large train. Treaty of Moscow (1920): Soviet Russia recognizes the independence of the Democratic Republic of Georgia, only to invade the country six months later. May 10 – Agnès Souret is elected "The most beautiful woman in France". May 15 – Russian Revolution: Russian White soldier Maria Bochkareva is executed in Soviet Russia. May 16 Canonization of Joan of Arc: Over 30,000 people attend the ceremony in Rome, including 140 descendants of Joan of Arc's family. Pope Benedict XV presides over the rite, for which the interior of St. Peter's Basilica in Rome is richly decorated. A referendum in Switzerland favors joining the League of Nations. May 17 French and Belgian troops leave the cities they have occupied in Germany. The first flight of Dutch air company KLM, from Amsterdam to London, takes place. May 19 – Mexican Revolution: Álvaro Obregón's troops enter Mexico City. May 20 – Mexican Revolution: Venustiano Carranza arrives in San Antonio Tlaxcalantongo; troops of Rodolfo Herrero attack him at night and shoot him. May 24 – Venustiano Carranza is buried in Mexico City; all of his mourning allies are arrested. Adolfo de la Huerta is elected provisional president. May 26 – Ganja revolt: Anti-Soviet opposition in the Azerbaijan SSR launches an abortive revolt in Ganja. May 27 – Tomáš Garrigue Masaryk becomes president of Czechoslovakia. May 29 – Floods at Louth, Lincolnshire in England kill 23. June June 4 – Treaty of Trianon: Peace is restored between the Allied Powers and Hungary, which loses 72% of its territory. June 5 – Bolshevik cavalry breaks through Polish and Ukrainian lines south of Kyiv, precipitating eventual withdrawal. June 12 – Polish–Soviet War: The Red Army retakes Kyiv. June 13 Essad Pasha Toptani, nominal ruler of Albania, is assassinated by Avni Rustemi in Paris. The United States Post Office Department rules that children may not be sent via parcel post. June 15