Qutub Minar is the tallest brick minaret in the world, and an important example of Indo-Islamic Architecture. The Qutub Minar is 72.5 metres (239 ft) high. The diameter of the base is 14.3 metres wide while the top floor measures 2.7 metres in diameter. It is listed as a UNESCO World Heritage Site along with surrounding buildings and monuments.
Inspired by the Minaret of Jam in Afghanistan and wishing to surpass it, Qutb-ud-din Aybak, the first Muslim ruler of Delhi, commenced construction of the Qutub Minar in 1193; but could only complete its basement. His successor, Iltutmish, added three more stories and, in 1368, Firuz Shah Tughluq constructed the fifth and the last story. The development of architectural styles from Aibak to Tuglak are quite evident in the minaret. Like earlier towers erected by the Ghaznavids and Ghurids in Afghanistan, the Qutub Mahal comprises several superposed flanged and cylindrical shafts, separated by balconies carried on Muqarnas corbels. The minaret is made of fluted red sandstone covered with intricate carvings and verses from the Qur'an. The Qutub Minar is itself built on the ruins of Lal Kot, the Red Citadel in the city of Dhillika, the capital of the Jat Tomars and the Chauhans, the last Hindu rulers of Delhi.
The purpose for building this beautiful monument has been speculated upon, apart from the usual role of a minaret - that of calling people for prayer in a mosque- in this case the Quwwat-ul-Islam mosque. Other reasons ascribed to its construction are as a tower of victory, a monument signifying the might of Islam, or a watch tower for defence. Controversy also surrounds the origins for the name of the tower. Many historians believe that the Qutub Minar was named after the first Turkish sultan, Qutb-ud-din Aibak but others contend that it was named in honour of Khwaja Qutb-ud-din Bakhtiar Kaki, a saint from Baghdad who came to live in India who was greatly venerated by Akhbar.