Arab intrusion into sindh
It started with a naval raid sent by kaliif umar companion of muhammad, which was destroyed by chAlukya-s near thAne [MT].
“It was only after 13 successive attempts that the Moslems finally breached and destroyed the Hindu kingdom of sindhu. .. But one major unanswered question of history arises: what was the cause of failure of the saindhava kingdom against ibn Qasim when it had until then pretty effectively resisted the Moslems for a period of nearly 75 years.” [MT]