Answer:
Historical perspectives change over time depending upon the biases of the writer.
Step-by-step explanation:
In historiography the main conflict is derived from the subjectivity that some writer could have. Because they are continuously analysing situations that occurred in the past, they cannot be present there.
Also, subjectivity tend to be found in the sources. In historiography, so many cases are based in interviews with old people of the zone, which also adds an subjective ingredient. All these tend to change the perspective of the historiographer.