India, July 17 -- The National Council of Educational Research and Training (NCERT) has said that a note on "history's darker period" explaining the rationale for detailing "religious intolerance" under the Delhi Sultanate and the Mughal eras has been added to the Class 8 social science textbook for the learners' benefit.

In a statement on Wednesday, NCERT said that chapters under "Tapestry of the Past" in Part 1 of the textbook include passages on warfare and instances of cruelty or brutality. It added that those happenings cannot be erased or denied, but it would be wrong to hold anyone today responsible for them.

The NCERT underlined that understanding the historical origin of cruel violence, abusive misrule, or misplaced ambitions o...