Also in 1930

• 6 of April - Gandhi raises a lump of mud and salt and declares, "With this, I am shaking the foundations of the British Empire," beginning the Salt Satyagraha.
• 18 of February - While studying photographs taken in January, Clyde Tombaugh discovers Pluto.
• 22 of April - The United Kingdom, Japan and the United States sign the London Naval Treaty regulating submarine warfare and limiting shipbuilding.