When the Western Roman Empire<span> fell in 476 C.E., a state of chaos encompassed Western Europe for many centuries. Essentially, the people of Western Europe needed some form of a political system to defend themselves. Thus, </span>feudalism developed<span>.</span>
He is known for his discovery of the photoelectric effect, for which he won the Nobel Prize for Physics in 1921. Einstein developed a theory of special and general relativity, which helped to complicate and expand upon theories that had been put forth by Isaac Newton over 200 years prior.
Sourcing provides information about an event which happened in the past.
Sourcing in history refers to a document from which we can take information about a historical event i. e. who wrote it and its need for its creation. If we have to study any historical event, we study the sources which was written by the people of that time about that event in their books. So for obtaining information about something that happened in the past we take sourcing as a reference and guidance. Example of sourcing are global sourcing and historical sourcing etc.