Answer:
1. 30, 1431 ( Joan of Arc being burned at the stake for heresy, May 30, 1431. Almost 20 years afterward, on his entry into Rouen in 1450, Charles VII ordered an inquiry into the trial. )
2. Harvard University * woo!* ( The oldest college in the United States is Harvard University, founded in 1636.)
3. Lancaster and York ( The Wars of the Roses were fought between the houses of Lancaster and York for the English throne. )
4. Hiroshima and Nagasaki ( The United States detonated two nuclear weapons over the Japanese cities of Hiroshima and Nagasaki on 6 and 9 August 1945, respectively. The two bombings killed between 129,000 and 226,000 people, most of whom were civilians, and remain the only use of nuclear weapons in armed conflict. )