Well no one cares about "arrival" of Islam. Invaders didn't come to "spread Islam" ... They came for their own purposes. Islam spreaded in India due to peaceful Sufi Saints... Islam taught Indians how to see each and every human as "equal" , not on the basis of some stupid caste system of them...Indians who were peaceful , dignified people (our ancestors) converted to Islam and started seeing everyone as equal. Gave women their rights and didn't burn them alive due to the death of their husband etc ... Elite hindus , that exploited the society and divided them into "lower caste" remain hindus (your ancestors) and kept exploiting Hindus uptil recently. Even now there are "untouchables" in your country , isn't it?