in form of seized crops and grains were stored in sultanate's granaries. Over time, farmers quit farming for income and shifted to subsistence farming, the general food supply worsened in north India, shortages increased and Delhi Sultanate witnessed increasingly worse and extended periods of famines. The Sultan banned private storage of food by anyone. Rationing system was introduced by Alauddin as shortages multiplied; however, the nobility and his army were exempt from the per family quota-based food rationing system. During these famines, Khalji's sultanate granaries and wholesale mandi system with price controls ensured sufficient food for his army, court officials and the urban population in Delhi. Price controls instituted by Khalji reduced prices, but also lowered wages to a point where ordinary people did not benefit from the low prices. The price control system collapsed shortly after the death of Alauddin Khalji, with prices of various agriculture products and wages doubling to quadrupling within a few years. Historical impact The tax system introduced during the Khalji dynasty had a long term influence on Indian taxation system and state administration, Slavery Within Sultanate's capital city of Delhi, during Alauddin Khalji's reign, at least half of the population were slaves working as servants, concubines and guards for the Muslim nobles, amirs, court officials and commanders. Slavery in India during the Khalji dynasty, and later Islamic dynasties, included two groups of people - persons seized during military campaigns, and people who defaulted on their taxes. The institution of slavery and bondage labor became pervasive during the Khalji dynasty; male slaves were referred to as banda, qaid, ghulam, or burdah, while female slaves were called bandi, kaniz or laundi. Architecture Alauddin Khalji is credited with the early Indo-Mohammedan architecture, a style and construction campaign that flourished during Tughlaq dynasty. Among works completed during Khalji dynasty, are Alai Darwaza - the southern gateway of Qutb complex enclosure, the Idgah at Rapri, and the Jamat Khana Masjid in Delhi. The Alai Darwaza, completed in 1311, was included as part of Qutb Minar and its Monuments UNESCO World Heritage site in 1993. Perso-Arabic inscriptions on monuments have been traced to the Khalji dynasty era. Disputed historical sources Historians have questioned the reliability of historical accounts about the Khalji dynasty. Genuine primary sources and historical records from 1260 to 1349 period have not been found. One exception is the short chapter on Delhi Sultanate from 1302 to 1303