What the Rajputs really lacked was a spirit of aggression so conspicuous among the Muslims, and a will to force the war in the enemy's dominions and … - Ram Gopal

Beginning with the first Arab expedition against Thana near Bombay in A.D. 636 the Muslims only succeeded in establishing the Delhi Sultanate in AD 1206, that is, after prolonged and relentless efforts lasting as many as 570 years. The magnitude of the resistance offered by Indians can be easily comprehended if we remember that the duration of the effective Muslim rule over northern India, not to speak of the whole of India which was much less, if ever, lasted only 500 years (upto the death of Aurangzeb in AD 1707). ( p.101.)

Exclusive dependence on Persian and Arabic sources, for an account of Muslim invasions, is apt to produce an unbalanced view. The basic prejudices of the Muslim historians, who mostly belonged to the Ulema class, against other religions, make them reject any other account, however authentic, if it tends to subvert their basic belief in the might of Islam. The victories of the arms of Islam have been elaborately described while the reverses have either been conveniently omitted or painted as having ended in negotiations and tribute. Even when described, only minor details are made available. ( p.64.)

It is remarkable that none of these early Arab travellers speak about any Indian converts to Islam. The Merchant Sulaiman explicitly states: "In his time he knew neither Indians nor Chines who had accepted Islam or spoke Arabic.