The Indo-Islamic style of architecture emerged during the Delhi Sultanate period, combining elements from both Indian and Islamic architectural traditions.

Qutb-ud-din Aibak, the founder of the Delhi Sultanate, initiated the construction of the Qutub Minar in 1193.

The Qutub Minar is primarily constructed using red sandstone, which is a durable and readily available material in the region.

The Qutub Minar is characterized by its fluted minarets, which are cylindrical towers with vertical grooves.

The Qutub Minar was initially intended to serve as a watchtower, allowing for a panoramic view of the surrounding area.

Alauddin Khalji commissioned the construction of the Alai Darwaza, the grand entrance gate to the Qutub Minar complex.

The Alai Darwaza is notable for its use of horseshoe arches, a distinctive architectural element borrowed from Islamic architecture.

Firoz Shah Tughluq was responsible for the construction of the Hauz Khas Complex, which includes a water reservoir, a mosque, and a tomb.

The Hauz Khas Complex is primarily constructed using red sandstone, similar to the Qutub Minar.

The Hauz Khas Complex features ribbed domes, a distinctive architectural element characterized by intersecting arches.

The Hauz Khas Complex was primarily intended as a religious center, with the mosque and tomb serving as important spiritual landmarks.

Muhammad Tughluq initiated the construction of the Tughlaqabad Fort, a massive fortification intended to protect the city of Delhi.

The Tughlaqabad Fort is notable for its use of double walls, providing additional defense against potential attacks.

Firoz Shah Tughluq was responsible for the construction of the Firoz Shah Kotla, a fort complex located in Delhi.

The Firoz Shah Kotla is notable for its use of rubble masonry, a construction technique involving the use of irregular stones.