What happened on 22 April?

7 events from the Ever-When timeline, ranked by how much they mattered.

1. 1915 Second Battle of Ypres / first poison gas Germans use chlorine gas in mass attack — opens chemical warfare era.
2. 1519 Cortés lands at Veracruz Hernán Cortés disobeys Cuba governor's recall and lands ~600 men on the Mexican coast; scuttles his ships and marches inland.
3. 1904 Born: J. Robert Oppenheimer American physicist who led the Los Alamos lab building the atomic bomb.
4. 1453 Mehmed hauls his fleet over the hills Blocked by the chain, Mehmed has seventy ships dragged overland on greased wooden rollers — over a 200-foot ridge, in a single night — into the Golden Horn behind the boom. The def
5. 1970 First Earth Day First Earth Day environmental teach-in across the US.
6. 1500 Cabral reaches Brazil Portuguese fleet under Pedro Álvares Cabral, bound for India, lands on the Brazilian coast; Portugal claims and colonises Brazil.
7. 1529 Treaty of Saragossa Spain and Portugal partition the Pacific; complements Tordesillas; resolves dispute over the Moluccas.