The 'double dome', an important feature of Indo-Islamic architecture, was first used in India in buildings of the:

The double dome was first used in India in tombs built during the Lodi period (late 15th and early 16th century), in Delhi.

What is a double dome?

A double dome has two shells: an inner dome and an outer dome, with an empty space between them.

The inner dome gives a well-proportioned ceiling when seen from inside the building.

The outer dome can be built much higher, so that the building looks grand and impressive from outside.

This solved the problem that a single tall dome would make the interior look too high and narrow.

The technique was developed in Persia and Central Asia, and came to India from there.

Lodi examples:

• The tomb of Sikandar Lodi (1517-18) in the Lodi Gardens, Delhi, is usually cited as the earliest example of a double dome in India.
• Some historians also mention the tomb of Shihabuddin Taj Khan, of the same period.

Development under the Mughals:

• The double dome became a regular feature of Mughal architecture.
• Humayun's Tomb in Delhi has a large double dome of white marble.
• The Taj Mahal has a double dome, with a large gap between the inner and outer shells; the outer dome is much higher than the inner ceiling.
• The Gol Gumbaz of Bijapur, by contrast, has a single huge dome.

Other features of Lodi architecture:

• Tombs were built in two forms: octagonal and square.
• Domes were raised on high drums.
• Buildings were decorated with coloured glazed tiles and carved plaster.
• Gardens were laid out around some tombs.

Earlier Indo-Islamic features:

• The true arch and true dome appeared in Delhi in the late 13th and early 14th centuries.
• The Tughlaqs used sloping walls and simple, massive structures.

Why not the other options?

• ✗The Mamluk, Khalji and Tughlaq periods came before the Lodis and did not use the double dome.