Read history properly my friend. Muhammed of Ghori & not Muhamud of GHazni started the first islamiv rule in India. The Shudras were not Slaves in the first place, however the Muslim invaders killed all able bodied men and converted the local widows and children to slaves & Sx Slaves. Now if you are Ajlaf you know your acenstory MAY be from here. Sorry to hurt you, but this is the true history. Check in Google if you like.
