Some even ask how we know these facts. History is not just facts and dates. Historians generally agree that history proper begins when humans began to communicate by writing. Prehistory is the time before the invention of a recordable language. We have yet to see a letter from a T-Rex.
History is the written record of past events.
Historical research is dependent upon the individuals who write it. Everyone has their own perspective concerning an event. The viewpoint changes over time. In the last 50 years, perspectives about the past have changed. Today, people are interested in learning about individuals involved in common everyday events, such as women, slaves, factory workers, and low-ranking soldiers.