A historian is a person who researches and writes about the past, and who is widely considered as an expert on the subject matter.[1] Human history is studied by historians, who are concerned with the ongoing, systematic narration and investigation of previous events as they relate to the human race, as well as the study of all history as it unfolds over the course of time. The term "prehistoric historian" refers to someone who is interested in events that took place before recorded history was written down. Some historians are well-known due to their writings, as well as their schooling and experience. The term "historian" became a recognised professional vocation in the late nineteenth century, when research universities arose in Germany and other parts of the world.