Kellogg–Briand Pact
The Kellogg–Briand Pact, a treaty renouncing war as an instrument of national policy, went into effect. In Europe, the Holy See and the Kingdom of Italy signed the Lateran Treaty. The Idionymon law was passed in Greece to outlaw political dissent. Spain hosted the Ibero-American Exposition which featured pavilions from Latin American countries. The German airship LZ 127 "Graf Zeppelin" flew around the world in 21 days.