Historians such as Will Durant described Islamic invasions of India as "The bloodiest story in history.[228][229] Jadunath Sarkar contends that several Muslim invaders were waging a systematic jihad against Hindus in India to the effect that "Every device short of massacre in cold blood was resorted to in order to convert heathen subjects".[230] Hindus who converted to Islam were not immune to persecution due to the Muslim Caste System in India established by Ziauddin al-Barani in the Fatawa-i Jahandari,[4] where they were regarded as an "Ajlaf" caste and subjected to discrimination by the "Ashraf" castes.[231] Others argue that, during the Muslim conquests in the Indian subcontinent, Indian-origin religions experienced persecution from various Muslim conquerors[232] who massacred Hindus, Jains and Buddhists, attacked temples and monasteries, and forced conversions on the battlefield.[233]