Ghasi tuglak came to power in 1321 in Delhi. he defeated khalji rulers. His rule was marked with eleation of islamic architecture. One of the main features of this indo-islamic architecture was the creativity. It was the amalgamation of hindu and islamic styles of architecture.
Tomb of Ghiyas-uddin, tughlaquabad, Alai darwaja and Khirki masjid are some examples of this architecture.
Great palace of Tughlaquabad was made of golden bricks. The architecture was divided into two parts. One part was the fortress with the castle of Occident and the other part was the city for residents and military persons. The walls were made of sun-dried bricks. Semi-circular bastions with eyelets at regular intervals for watching over enemies. THe huge outer walls had sloping.
The outer portion of the tomb fortress is an irregular pentagon, with a spreading bastion at each angle. Major portion of the tomb is made with red sandstone, including dome, made of white marble. The outer walls are sloping at 75 degrees , like converging sides of a pyramid. Each side consists of a tall archway. Three of the archways are doorways and one was closed for accomodation for mirhab.
The typical style of combining of the arch and the beam in the tomb was first used in tughlaq dynasty