event of an attack on the other by a third party, for the next five years. April 25 – Rezā Khan is crowned Shah of Iran, under the name "Pahlevi". May May 4 – The United Kingdom general strike begins at midnight, in support of a strike by coal miners. May 9 Following the general strike which began May 4, martial law is declared in the United Kingdom. The French navy bombards Damascus, because of Druze riots. Explorer Richard E. Byrd and co-pilot Floyd Bennett claim to be the first to fly over the North Pole in the Josephine Ford monoplane, taking off from Spitsbergen, Norway and returning 15 hours and 44 minutes later. Both men are immediately hailed as national heroes, though some experts have since been skeptical of the claim, believing that the plane was unlikely to have covered the entire distance and back in that short an amount of time. An entry in Byrd's diary, discovered in 1996, suggested that the plane actually turned back 150 miles short of the North Pole, due to an oil leak. May 10 – Planes piloted by Major Harold Geiger and Horace Meek Hickam, students at the United States Air Corps Tactical School, collide in mid-air at Langley Field, Virginia. May 12 Roald Amundsen and his crew fly over the North Pole, in the airship Norge. UK General Strike 1926: In the United Kingdom, a general strike by trade unions ends. May 12–14 – May Coup: Józef Piłsudski takes over in Poland. May 18 – Evangelist Aimee Semple McPherson disappears, while visiting a Venice, California beach. May 20 – The United States Congress passes the Air Commerce Act, licensing pilots and planes. May 23 – The first Lebanese constitution is established. May 25 – At least 165 persons (144 confirmed) die in the Mount Tokachi volcano eruption in Hokkaido, Japan, according to the Japanese government official report. May 26 – The Rif War ends, when Rif rebels surrender in Morocco. May 28 – The 1926 coup d'état, commanded by Manuel Gomes da Costa in Portugal, installs the Ditadura Nacional (National Dictatorship), followed by António de Oliveira Salazar's Estado Novo. June June 4 – Ignacy Mościcki becomes president of Poland. June 7 – Liberal politician Carl Gustaf Ekman succeeds Rickard Sandler, as Prime Minister of Sweden. June 29 – Arthur Meighen briefly returns to office as Prime Minister of Canada during the