The historian Ziauddin Barani, a conservative Muslim intellectual of the Delhi Sultanate period, criticized the Sultans (like Alauddin Khalji and Muhammad bin Tughlaq) for not strictly adhering to Islamic law (Sharia) as the sole basis for governance. He noted that the Sultans often formulated their own regulations, known as 'Zawabit', based on political and administrative requirements, which sometimes deviated from or supplemented the Sharia. This practice of the Sultan creating laws independent of, or in addition to, the strict religious code was a major reason for Barani to view the state as not being 'truly Islamic' according to his interpretation.