According to Hindu tradition, the source of the Ganges River is the god Shiva's hair (D).
The correct answer to this open question is the following.
You forgot to mention or attach the lenses that you refer to in the question. However, we can answer is general terms.
When we talk about the term "lens" in research, we are referring to a specific perspective to examine the topic at hand or the study. We can use philosophical lenses, economic, organizational, social, or psychological theories.
So we do not what lens you chose, but whatever your choice was, this lens might change how you approach researching your topic, thus affecting the historical narrative, because that particular approach is going to offer you different sources, authors, perspectives, and research lines to be followed. Your historic narrative would suffer modifications because you will have so many approaches to include in your research.
