With the arrival of islamic rulers and subsequent conquest of Delhi throne by the 12th century, Indian architecture underwent a massive change. Though new elements were introduced majorly, the local architects retained certain flavours of the local architectural traditions as well. Thus a confluence of persian and Indian elements can be seen which is known as Indo-Islamic or Indo-Sarcenic architecture. It was introduced during Delhi sultanate period and evolved during the reign of Mughals

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Striking and unique features:

• Arches and Domes: used which is known as ‘arcuade’ style of architecture replaced the traditional Trabeat style of architecture.
• Minars: are used around the mosques and the mausoleums.
• Mortar: used as a cementing agent in their constructions.
• Natural Figurines: were used. Human and Animal figures are avoided.
• Spaciousness, massiveness and breadth of buildings and structures.
• Calligraphy: used as a means of decoration as well as arabesque method which involved the use of geometrical ornamentation. Further, the decorations followed a symmetrical pattern.
• Jaali work: a feature allowing light into the structures.
• Water: pools in the premises of the building used for cooling, decorative and religious purposes.
• Charbagh style of gardening: in which a square block is divided into 4 adjacent identical gardens.
• Foreshortening technique: in the buildings, such that the inscriptions appear to be closer than it really is.
• Pietra Dura and Mosaic designs: using cut and fitted highly polished gems and stones.

Some of the examples illustrating the same are:

• Delhi Sultanate: Qutb Minar, Quwwat Ul Islam Mosque, Alai Darwaza, Lodi Gardens etc.,
• Mughals: Taj Mahal, Red fort, Fatehpur sikri etc.,
• Deccan sultanate: Gol Gumbaz, Char minar, Golconda fort etc., 
• Provincial: Adina Mosque, Atala Mosque etc.,

Conclusion

Architecturally, a mix of many techniques, stylised shapes and surface decorations evolved through a continuous amalgamation of architectural elements from the various styles. Indo Islamic Architecture flourished in entire India over time. Its influence could be seen in southern Indian structures like Mysore palace and in Various buildings under British like Parliament, Victoria terminus etc.