1) The American Civil Rights Movement, led by figures like Martin Luther King Jr., fought for equal rights and helped bring about significant social and legislative changes.

2) The concept of reinsurance, which is insurance for insurance companies, originated in the 17th century.

3) The ancient city of Athens, Greece, is often considered the birthplace of democracy, where citizens had a say in the decision-making process.

4) In Norse mythology, the Valkyries are divine maidens who serve Odin, the chief god. They are responsible for selecting warriors worthy of entering Valhalla and escorting them to the afterlife. They are often depicted as powerful and beautiful figures, riding winged horses and wielding spears.