1519 - Envoys of Montezuma II attended the first Easter mass in Central America.
1558 - Mary, Queen of Scotland, married the French dauphin, Francis.
1877 - Russia declared war on the Ottoman Empire.
1915 - During World War I, the Ottoman Turkish Empire began the mass deportation of Armenians.
1916 - Irish nationalist launched the Easter Rebellion against British occupation forces. They were overtaken several days later.
1953 - Winston Churchill was knighted by Queen Elizabeth II.
1970 - The People's Republic of China launched its first satellite.
1973 - Albert Sabin reported that herpesviruses were factors in nine kinds of cancer.
1989 - Thousands of students began striking in Beijing.
1990 - The space shuttle Discovery blasted off from Cape Canaveral. It was carrying the $1.5 billion Hubble Space Telescope.